ArgumentPromotion: correctly transfer TBAA tags and alignments.

We used to use std::map<IndicesVector, LoadInst*> for OriginalLoads, and when we
try to promote two arguments, they will both write to OriginalLoads causing
created loads for the two arguments to have the same original load. And the same
tbaa tag and alignment will be put to the created loads for the two arguments.

The fix is to use std::map<std::pair<Argument*, IndicesVector>, LoadInst*>
for OriginalLoads, so each Argument will write to different parts of the map.

PR17906


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194846 91177308-0d34-0410-b5e6-96231b3b80d8
Reimplement r194843 in a slightly less broken way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194848 91177308-0d34-0410-b5e6-96231b3b80d8
Path: Recognize COFF import library file magic.

Summary: Make identify_magic to recognize COFF import file.

Reviewers: Bigcheese

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2165

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194852 91177308-0d34-0410-b5e6-96231b3b80d8