Changes

[MachineVerifier]  Improve checks of target instructions operands.
While working with a patch for instruction selection, the splitting of a 
large immediate ended up begin treated incorrectly by the backend. Where
a register operand should have been created, it instead became an
immediate. To my surprise the machine verifier failed to report this,
which at the time would have been helpful.
This patch improves the verifier so that it will report this type of
error.
This patch XFAILs CodeGen/SPARC/fp128.ll, which has been reported at 
https://bugs.llvm.org/show_bug.cgi?id=44091
Review: thegameg, arsenm, fhahn https://reviews.llvm.org/D63973

[NFC] Tidy-ups to TimeProfiler.cpp
Remove unused include Make fields const where possible Move
initialisation to initialiser list
Differential Revision: https://reviews.llvm.org/D70904

Mark some tests as xfail on AArch64 Linux
I have either opened new bug reports for these tests, or added links to 
existing bugs.
This should help make the lldb-aarch64-ubuntu buildbot green (there will 
still be some unexpected passes that someone should look into, but those 
can be handled later).

[LiveDebugValues] Introduce entry values of unmodified params
The idea is to remove front-end analysis for the parameter's value 
modification and leave it to the value tracking system. Front-end in
some cases marks a parameter as modified even the line of code that
modifies the parameter gets optimized, that implies that this will cover
more entry values even. In addition, extending the support for modified
parameters will be easier with this approach.
Since the goal is to recognize if a parameter’s value has changed, the
idea at very high level is: If we encounter a DBG_VALUE other than the
entry value one describing the same variable (parameter), we can assume
that the variable’s value has changed and we should not track its entry
value any more. That would be ideal scenario, but due to various LLVM
optimizations, a variable’s value could be just moved around from one
register to another
(and there will be additional DBG_VALUEs describing the same variable),
so we have to recognize such situation (otherwise, we will lose a lot of
entry values) and salvage the debug entry value.
Differential Revision: https://reviews.llvm.org/D68209

ImplicitNullChecks: Don't add a dead definition of DepMI as live-in
This is one of the fixes needed to reapply D68267 which improves
verification of live-in lists.
Review: craig.topper https://reviews.llvm.org/D70434

Temporarily run machine-verifier once in test/CodeGen/SPARC/fp128.ll, so
that it XFAIL:s also without expensive checks.
See https://reviews.llvm.org/D63973

[asan] Remove debug locations from alloca prologue instrumentation
Summary: This fixes https://llvm.org/PR26673
"Wrong debugging information with -fsanitize=address" where asan
instrumentation causes the prologue end to be computed incorrectly:
findPrologueEndLoc, looks for the first instruction with a debug
location to determine the prologue end.  Since the asan instrumentation
instructions had debug locations, that prologue end was at some
instruction, where the stack frame is still being set up.
There seems to be no good reason for extra debug locations for the asan
instrumentations that set up the frame; they don't have a natural source
location.  In the debugger they are simply located at the start of the
function.
For certain other instrumentations like
-fsanitize-coverage=trace-pc-guard the same problem persists - that
might be more work to fix, since it looks like they rely on locations of
the tracee functions.
This partly reverts aaf4bb239487e0a3b20a8eaf94fc641235ba2c29
"[asan] Set debug location in ASan function prologue" whose motivation
was to give debug location info to the coverage callback. Its test only
ensures that the call to @__sanitizer_cov_trace_pc_guard is given the
correct source location; as the debug location is still set in 
ModuleSanitizerCoverage::InjectCoverageAtBlock, the test does not break. 
So -fsanitize-coverage is hopefully unaffected - I don't think it should 
rely on the debug locations of asan-generated allocas.
Related revision: 3c6c14d14b40adfb581940859ede1ac7d8ceae7a
"ASAN: Provide reliable debug info for local variables at -O0."
Below is how the X86 assembly version of the added test case changes. We
get rid of some .loc lines and put prologue_end where the user code
starts.
```diff
--- 2.master.s	2019-12-02 12:32:38.982959053 +0100
+++ 2.patch.s	2019-12-02 12:32:41.106246674 +0100
@@ -45,8 +45,6 @@
	.cfi_offset %rbx, -24
	xorl	%eax, %eax
	movl	%eax, %ecx
- .Ltmp2:
- 	.loc	1 3 0 prologue_end      # 2.c:3:0
	cmpl	$0, __asan_option_detect_stack_use_after_return
	movl	%edi, 92(%rbx)          # 4-byte Spill
	movq	%rsi, 80(%rbx)          # 8-byte Spill
@@ -57,9 +55,7 @@
	callq	__asan_stack_malloc_0
	movq	%rax, 72(%rbx)          # 8-byte Spill
.LBB1_2:
- 	.loc	1 0 0 is_stmt 0         # 2.c:0:0
	movq	72(%rbx), %rax          # 8-byte Reload
- 	.loc	1 3 0                   # 2.c:3:0
	cmpq	$0, %rax
	movq	%rax, %rcx
	movq	%rax, 64(%rbx)          # 8-byte Spill
@@ -72,9 +68,7 @@
	movq	%rax, %rsp
	movq	%rax, 56(%rbx)          # 8-byte Spill
.LBB1_4:
- 	.loc	1 0 0                   # 2.c:0:0
	movq	56(%rbx), %rax          # 8-byte Reload
- 	.loc	1 3 0                   # 2.c:3:0
	movq	%rax, 120(%rbx)
	movq	%rax, %rcx
	addq	$32, %rcx
@@ -99,7 +93,6 @@
	movb	%r8b, 31(%rbx)          # 1-byte Spill
	je	.LBB1_7
# %bb.5:
- 	.loc	1 0 0                   # 2.c:0:0
	movq	40(%rbx), %rax          # 8-byte Reload
	andq	$7, %rax
	addq	$3, %rax
@@ -118,7 +111,8 @@
	movl	%ecx, (%rax)
	movq	80(%rbx), %rdx          # 8-byte Reload
	movq	%rdx, 128(%rbx)
-	.loc	1 4 3 is_stmt 1         # 2.c:4:3
+.Ltmp2:
+	.loc	1 4 3 prologue_end      # 2.c:4:3
	movq	%rax, %rdi
	callq	f
	movq	48(%rbx), %rax          # 8-byte Reload
```
Reviewers: eugenis, aprantl
Reviewed By: eugenis
Subscribers: ormris, aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70894

[lldb] Move register info "augmentation" from gdb-remote into ABI
Summary: Previously the ABI plugin exposed some "register infos" and the 
gdb-remote code used those to fill in the missing bits. Now, the
"filling in" code is in the ABI plugin itself, and the gdb-remote code 
just invokes that.
The motivation for this is two-fold: a) the "augmentation" logic is
useful outside of process gdb-remote. For
 instance, it would allow us to avoid repeating the register number
 definitions in minidump code. b) It gives more implementation freedom
to the ABI classes. Now that
 these "register infos" are essentially implementation details, classes
 can use other methods to obtain dwarf/eh_frame register numbers -- for
 instance they can consult llvm MC layer.
Since the augmentation code was not currently tested anywhere, I took 
the opportunity to create a simple test for it.
Reviewers: jasonmolenda, clayborg, tatyana-krasnukha
Subscribers: aprantl, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70906

[lldb] Remove tab from TestReturnValue.py
Mixing tabs and spaces makes Python exit with this error:
  File
"llvm/lldb/packages/Python/lldbsuite/test/functionalities/return-value/TestReturnValue.py",
line 23
   return (self.getArchitecture() == "aarch64" and self.getPlatform() ==
"linux")
                                                                        
       ^ TabError: inconsistent use of tabs and spaces in indentation

[DWARF] Add support for parsing/dumping section indices in location
lists
Summary: This does exactly what it says on the box. The only small
gotcha is the section index computation for offset_pair entries, which
can use either the base address section, or the section from the
offset_pair entry. This is to support both the cases where the base
address is relocated
(points to the base of the CU, typically), and the case where the base 
address is a constant (typically zero) and relocations are on the 
offsets themselves.
Reviewers: dblaikie, JDevlieghere, aprantl, SouraVX
Subscribers: hiraditya, llvm-commits, probinson
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70540

Fixup 6d18e53: xfail TestShowLocationDwarf5.py properly
Forgot to squash this...

[clang][CodeGen] Make use of cc1 instead of clang in the tests

[lldb][NFC] Test going up/down one line in the multiline expression
editor

[OpenCL] Fix mangling of single-overload builtins
Commit 9a8d477a0e0 ("[OpenCL] Add builtin function attribute handling",
2019-11-05) stopped Clang from mangling single-overload builtins, which
is incorrect.

[CodeGen] Move ARMCodegenPrepare to TypePromotion
Convert ARMCodeGenPrepare into a generic type promotion pass by:
- Removing the insertion of arm specific intrinsics to handle narrow
 types as we weren't using this.
- Removing ARMSubtarget references.
- Now query a generic TLI object to know which types should be
 promoted and what they should be promoted to.
- Move all codegen tests into Transforms folder and testing using opt
 and not llc, which is how they should have been written in the
 first place...
The pass searches up from icmp operands in an attempt to safely promote
types so we can avoid generating unnecessary unsigned extends during DAG
ISel.
Differential Revision: https://reviews.llvm.org/D69556

[lldb] Remove all remaining tabs from TestReturnValue.py
I assumed this was just a single typo, but it seems we actually have a
whole bunch of tabs in this file which cause Python to complain about
mixing tabs and spaces.