Changes

[LegalizeDAG] Return true from ExpandNode for some nodes that don't have
expand support.
These nodes have a FIXME that they only get here because a Custom 
handler returned SDValue() instead of the original Op.
Even though we aren't expanding them, we should return true here to 
prevent ConvertNodeToLibcall from also trying to process them until the
FIXME has been addressed.
I'm hoping to add checking to ConvertNodeToLibcall to make sure we don't
give it nodes it doesn't have support for.

AvoidBindCheck.cpp: Fix GCC 5.3 build errors
It was failing with:
clang-tools-extra/clang-tidy/modernize/AvoidBindCheck.cpp:61:29: error:
declaration of ‘clang::tidy::modernize::{anonymous}::CaptureMode
clang::tidy::modernize::{anonymous}::BindArgument::CaptureMode’
[-fpermissive]
  CaptureMode CaptureMode = CM_None;
                            ^ 
clang-tools-extra/clang-tidy/modernize/AvoidBindCheck.cpp:38:6: error:
changes meaning of ‘CaptureMode’ from ‘enum
clang::tidy::modernize::{anonymous}::CaptureMode’ [-fpermissive]
enum CaptureMode { CM_None, CM_ByRef, CM_ByValue, CM_InitExpression };
     ^

AvoidBindCheck.cpp: Fix unused variables warning

[lldb][NFC] Remove ThreadSafeSTLVector and ThreadSafeSTLMap and their
use in ValueObjectSynthetic
Summary: ThreadSafeSTLVector and ThreadSafeSTLMap are not useful for
achieving any degree of thread safety in LLDB and should be removed
before they are used in more places. They are only used (unsurprisingly
incorrectly) in
`ValueObjectSynthetic::GetChildAtIndex`, so this patch replaces their
use there with a simple mutex with which we guard the related data
structures. This doesn't make ValueObjectSynthetic::GetChildAtIndex any
more thread-safe, but on the other hand it at least allows us to get rid
of the ThreadSafeSTL* data structures without changing the observable
behaviour of ValueObjectSynthetic (beside that it is now a few bytes
smaller).
Reviewers: labath, JDevlieghere, jingham
Reviewed By: labath
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70845

[UpdateTestChecks] Fix parsing of RUN: lines with line continuations
I accidentally broke this in d9542db49e90457de62af3bfe395aaf4c47b68a5
due to incorrectly placed parentheses.

[llvm][bindings][go] Fix typo

[NFC] Slightly improve wording in the comments
Reviewed by: hokein
Differential Revision: https://reviews.llvm.org/D70943