Changes

List implicit operator== after implicit destructors in a vtable.
Summary: We previously listed first declared members, then implicit
operator=, then implicit operator==, then implicit destructors. Per
discussion on https://github.com/itanium-cxx-abi/cxx-abi/issues/88, put
the implicit equality comparison operators at the very end, after all
special member functions.
This reinstates add2b7e44ada46f30715b5c48823a9e9e317e0c3, reverted in 
commit 89e43f04ba87a0da6e94863db149669c7536486b, with a fix for 32-bit 
targets.
Reviewers: rjmccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72897

[Concepts] Placeholder constraints and abbreviated templates
This patch implements P1141R2 "Yet another approach for constrained
declarations".
General strategy for this patch was:
- Expand AutoType to include optional type-constraint, reflecting the
wording and easing the integration of constraints.
- Replace autos in parameter type specifiers with invented parameters in
GetTypeSpecTypeForDeclarator, using the same logic
 previously used for generic lambdas, now unified with abbreviated
templates, by:
 - Tracking the template parameter lists in the Declarator object
 - Tracking the template parameter depth before parsing function
declarators (at which point we can match template
   parameters against scope specifiers to know if we have an explicit
template parameter list to append invented parameters
   to or not).
- When encountering an AutoType in a parameter context we check a stack
of InventedTemplateParameterInfo structures that
 contain the info required to create and accumulate invented template
parameters (fields that were already present in
 LambdaScopeInfo, which now inherits from this class and is looked up
when an auto is encountered in a lambda context).
Differential Revision: https://reviews.llvm.org/D65042

[mlir][Linalg] Add tensor support to Linalg EDSC Builders
Summary: This diff extends the Linalg EDSC builders so we can easily
create mixed tensor/buffer linalg.generic ops. This is expected to be
useful for HLO -> Linalg lowering.
The `StructuredIndexed` struct is made to derive from `ValueHandle` and
can now capture a type + indexing expressions. This is used to represent
return tensors.
Pointwise unary and binary builders are extended to allow both output
buffers and return tensors. This has implications on the number of
region arguments.
Reviewers: ftynse, herhut, hanchung, asaadaldien, stellaraccident
Reviewed By: asaadaldien
Subscribers: merge_guards_bot, mehdi_amini, rriddle, jpienaar, burmako,
shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, aartbik,
liufengdb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72863

Revert "[mlir][Linalg] Add tensor support to Linalg EDSC Builders"
This reverts commit 89e19e8eddd6dd0dc38d595b6784fb9ce65d9972.
This committed a stale version of the diff
https://reviews.llvm.org/D72863 .. I apologize, reverting.

[clang-tidy] Fix check for generic lambda invented template parameters
clang-tidy previously relied on there being no identifier for a
TemplateTypeParmDecl for checking whether 'decltype(x)' should be
inserted, instead of checking whether or not it is implicit.
D65042 added new names for invented generic lambda template parameters,
rendering that check incorrect.

[AArch64] Don't generate gpr CSEL instructions in early-ifcvt if
regclasses aren't compatible.
In GlobalISel we may in some unfortunate circumstances generate PHIs
with operands that are on separate banks. If-conversion doesn't
currently check for that case and ends up generating a CSEL on AArch64
with incorrect register operands.
Differential Revision: https://reviews.llvm.org/D72961

[clang/Darwin] Remove __llvm_profile_counter_bias from export list for
profiling
Do not export __llvm_profile_counter_bias when profiling is enabled 
because this symbol is hidden and cannot be exported.
Should fix this bot error:
``` URL:
http://green.lab.llvm.org/green/job/clang-stage1-RA/5678/consoleFull
Problem: Command Output (stdout):
-- ld: warning: cannot export hidden symbol ___llvm_profile_counter_bias 
from
/Users/buildslave/jenkins/workspace/clang-stage1-RA/clang-build/lib/clang/11.0.0/lib/darwin/libclang_rt.profile_osx.a(InstrProfilingBiasVar.c.o) 
ld: warning: cannot export hidden symbol ___llvm_profile_counter_bias 
from
/Users/buildslave/jenkins/workspace/clang-stage1-RA/clang-build/lib/clang/11.0.0/lib/darwin/libclang_rt.profile_osx.a(InstrProfilingBiasVar.c.o)
```

[Concepts] Constraint Satisfaction Caching
Add a simple cache for constraint satisfaction results. Whether or not
this simple caching would be permitted in final C++2a is currently being
discussed but it is required for acceptable performance so we use it in
the meantime, with the possibility of adding some cache invalidation
mechanisms later.
Differential Revision: https://reviews.llvm.org/D72552

[libc++] Make sure std::is_scalar returns true for block types
Summary: The compiler already treats them as scalar types, so the
library should too. Furthermore, this allows blocks to be used in more
places, for example in std::optional, which requires an object type.
rdar://problem/57892832
Reviewers: dexonsmith, EricWF, mclow.lists Differential Revision:
https://reviews.llvm.org/D72708

[test] Use yaml2obj -o %t instead of > %t
To improve consistency and avoid unneeded shell feature (output 
redirection).
While here, make other changes to improve consistency
--docnum 1 => --docnum=1
-docnum=x => --docnum=x

[polly] XFAIL memset_null.ll.
I'm working on a patch, but not sure how long it'll take.

[Concepts] Fix circular AST->Sema dependency in ASTConcept.cpp
Remove inappropriate Sema include in ASTConcept.cpp introduced by D72552
for the finer-grained includes actually needed.

Revert "[Concepts] Placeholder constraints and abbreviated templates"
This temporarily reverts commit e03ead6771fc97b11cb0c94b7f023142184ad25f 
because it breaks LLDB.
http://lab.llvm.org:8011/builders/lldb-x86_64-debian/builds/3356 
http://lab.llvm.org:8011/builders/lldb-x64-windows-ninja/builds/12872 
http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/6407/

[llvm] NFC: fix trivial typos in documents
Reviewers: hans, Jim
Reviewed By: Jim
Subscribers: jvesely, nhaehnle, mgorny, arphaman, bmahjour, kerbowa,
llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73017

[libcxxabi] NFC: Fix trivial typos in comments
Reviewers: EricWF, mclow.lists, Jim
Reviewed By: Jim
Subscribers: mgorny, christof, ldionne, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D72151