InstCombine: merge constants in both operands of icmp.

Transform:
    icmp X+Cst2, Cst
into:
    icmp X, Cst-Cst2
when Cst-Cst2 does not overflow, and the add has nsw.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204912 91177308-0d34-0410-b5e6-96231b3b80d8
IRTests/InstructionsTest.cpp: Avoid initializer list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204914 91177308-0d34-0410-b5e6-96231b3b80d8
SmallVector<3> may be used here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204915 91177308-0d34-0410-b5e6-96231b3b80d8
Untabify.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204916 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Implement custom MCELFStreamer.

This allows us to insert some hooks before emitting data into an actual object file.
For example, we can capture the register usage for a translation unit by overriding
the EmitInstruction method. The register usage information is needed to generate
.reginfo and .Mips.options ELF sections.
    
No functional changes.
    
Differential Revision: http://llvm-reviews.chandlerc.com/D3129


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204917 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] NaCl should now use the custom MipsELFStreamer (recently added) in spite
of MCELFStreamer.

This is so that changes to MipsELFStreamer will automatically propagate through
its subclasses.

No functional changes (MipsELFStreamer has the same functionality of MCELFStreamer
at the moment).

Differential Revision: http://llvm-reviews.chandlerc.com/D3130


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204918 91177308-0d34-0410-b5e6-96231b3b80d8