[mips] MIPS-IV is broadly the same as MIPS64 so duplicate all -mcpu=mips64 tests with -mcpu=mips4 as a starting point

Summary:
Two exceptions to this:
  test/CodeGen/Mips/octeon.ll
  test/CodeGen/Mips/octeon_popcnt.ll
these test extensions to MIPS64

One test is altered for MIPS-IV:
  test/CodeGen/Mips/mips64countleading.ll
    Tests dclo/dclz which were added in MIPS64. The MIPS-IV version tests
    that dclo/dclz are not emitted.

Four tests fail and are not in this patch:
  test/CodeGen/Mips/abicalls.ll
  test/CodeGen/Mips/fcopysign-f32-f64.ll
  test/CodeGen/Mips/fcopysign.ll
  test/CodeGen/Mips/stack-alignment.ll

Depends on D3343

Reviewers: matheusalmeida, vmedic

Reviewed By: vmedic

Differential Revision: http://reviews.llvm.org/D3344

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206185 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Fix fcopysign for MIPS-IV and add the test.

Summary:
This was another incorrect use of hasMips64() vs isGP64bit().

Depends on D3344

Reviewers: matheusalmeida, vmedic

Reviewed By: vmedic

Differential Revision: http://reviews.llvm.org/D3347

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206187 91177308-0d34-0410-b5e6-96231b3b80d8
tools: fix heap-buffer-overrun detected via ASAN

Once the auxiliary fields relating to the filename have been inspected, any
following auxiliary fields need not be visited as they have been consumed (the
following fields comprise the filepath as a single unit).

Adjust the test to catch this even if ASAN is not enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206190 91177308-0d34-0410-b5e6-96231b3b80d8
Fix up MCFixup::getAccessVariant to handle unary expressions.

This allows correct relocations to be generated for a symbolic
address that is being adjusted by a negative constant. Since r204294,
such expressions have triggered undefined behavior when LLVM was built
without assertions.

Credit goes to Rafael for this patch; I'm submitting it on his behalf
as he is on vacation this week.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206192 91177308-0d34-0410-b5e6-96231b3b80d8