Readobj: If NumbersOfSections is 0xffff, it's an COFF import library.

0xffff does not mean that there are 65535 sections in a COFF file but
indicates that it's a COFF import library. This patch fixes SEGV error
when an import library file is passed to llvm-readobj.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194844 91177308-0d34-0410-b5e6-96231b3b80d8
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