DWARF emission: Remove unnecessary/redundant DIE reference code

The default case at the end of the switch handles this just fine.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193374 91177308-0d34-0410-b5e6-96231b3b80d8
lto.h: Use lto_bool_t instead of int to restore the ABI

This reverts commit r193255 and instead creates an lto_bool_t typedef
that points to bool, _Bool, or unsigned char depending on what is
available.  Only recent versions of MSVC provide a stdbool.h header.

Reviewers: rafael.espindola

Differential Revision: http://llvm-reviews.chandlerc.com/D2019

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193377 91177308-0d34-0410-b5e6-96231b3b80d8
MCStreamer: Reimplement the virtual EmitRawText as a protected member, EmitRawTextImpl, to avoid string literal ambiguities

Also improve the implementation of EmitRawText(Twine) so it doesn't
bother using the SmallString buffer if the Twine is a simple StringRef
anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193378 91177308-0d34-0410-b5e6-96231b3b80d8