Add a flag to disable the ARM64DeadRegisterDefinitionsPass

This patch adds a -arm64-dead-def-elimination flag so that it is possible to
disable dead definition elimination. Includes test case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206207 91177308-0d34-0410-b5e6-96231b3b80d8
Fix for codegen bug that could cause illegal cmn instruction generation

In rare cases the dead definition elimination pass code can cause illegal cmn
instructions when it replaces dead registers on instructions that use
unmaterialized frame indexes. This patch disables the dead definition
optimization for instructions which include frame index operands.

rdar://16438284

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206208 91177308-0d34-0410-b5e6-96231b3b80d8
[cleanup] Run clang-format over most of YAMLParser.h to fix a bunch of
small formatting inconsistencies with the rest of LLVM and even this
file. I looked at all the changes and they seemed like just better
formatting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206209 91177308-0d34-0410-b5e6-96231b3b80d8
Re-apply r206096 after investigating the gdb buildbot failure.
Thanks to dblaikie for updating the testcase!

Debug info: (bugfix) C++ C/Dtors can be compiled to multiple functions,
therefore, their declaration cannot have one DW_AT_linkage_name.
The specific instances however can and should have that attribute.

This patch reorders the code in DwarfUnit::getOrCreateSubprogramDIE()
to emit linkage names for C/Dtors.

rdar://problem/16362674.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206210 91177308-0d34-0410-b5e6-96231b3b80d8
[ARM64][MC] Set the default CPU to cyclone when initilizating the MC layer.
This matches that ARM64Subtarget does for now.

This is related to <rdar://problem/16573920>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206211 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "Revert r206045, "Fix shift by constants for vector.""

Fix cases where the Value itself is used, and not the constant value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206214 91177308-0d34-0410-b5e6-96231b3b80d8