[X86] New and improved VZeroUpperInserter optimization.

- Adds support for inserting vzerouppers before tail-calls.
  This is enabled implicitly by having MachineInstr::copyImplicitOps preserve
  regmask operands, which allows VZeroUpperInserter to see where tail-calls use
  vector registers.

- Fixes a bug that caused the previous version of this optimization to miss some
  vzeroupper insertion points in loops. (Loops-with-vector-code that followed
  loops-without-vector-code were mistakenly overlooked by the previous version).

- New algorithm never revisits instructions.

Fixes <rdar://problem/16228798>



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204021 91177308-0d34-0410-b5e6-96231b3b80d8
Rename PBQP RegAllocSolver local variables to conform to LLVM coding style.

No functional change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204022 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-readobj: Add test for COFF auxiliary symbols as used by C++/CLI

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204023 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-readobj: Print referred symbol name for CLR token definition

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204024 91177308-0d34-0410-b5e6-96231b3b80d8
Deleted copy-constructor/copy-assignment broke a buildbot. Removing while I
investigate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204025 91177308-0d34-0410-b5e6-96231b3b80d8
Test case

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204026 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Improve reuse of file table entries in asm debug info

The previous deduping strategy was woefully inadequate - it only
considered the most recent file used and avoided emitting a duplicate in
that case - never considering the a/b/a scenario.

It was also lacking when it came to directory paths as the previous
filename would never match the current if the filename had been split
into file and directory components.

This change builds caching functionality into the line table at the
lowest level in an optional form (a file number of 0 indicates that one
should be chosen and returned) and will eventually be reused by the
normal source level debugging DWARF emission.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204027 91177308-0d34-0410-b5e6-96231b3b80d8