InstCombine: Reimplementation of visitUDivOperand

This transform was originally added in r185257 but later removed in
r185415.  The original transform would create instructions speculatively
and then discard them if the speculation was proved incorrect.  This has
been replaced with a scheme that splits the transform into two parts:
preflight and fold.  While we preflight, we build up fold actions that
inform the folding stage on how to act.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185667 91177308-0d34-0410-b5e6-96231b3b80d8
MC: Add .section directive to COFF

Supports GAS flags "abdnrswxy". No support for alignment or subsections.

Fixes PR16366.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185669 91177308-0d34-0410-b5e6-96231b3b80d8
Initialize object file info before output streamer

r179494 switched to using the object file info to retrieve the default text
section for some MC streamers. It is possible that initializing an MC
streamer can request sections before the object file info is initialized
when the AutoInitSections flag is set on the streamer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185670 91177308-0d34-0410-b5e6-96231b3b80d8