Use simple section names for COMDAT sections on COFF.

With this patch we use simple names for COMDAT sections (like .text or .bss).
This matches the MSVC behavior.

When merging it is the COMDAT symbol that is used to decide if two sections
should be merged, so there is no point in building a fancy name.

This survived a bootstrap on mingw32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195798 91177308-0d34-0410-b5e6-96231b3b80d8
[PM] Remove the underspecified 'getRoot' method from CallGraph. It's
only user was an ancient SCC printing bit of the opt tool which really
should be walking the call graph the same way the CGSCC pass manager
does.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195800 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64] Add support for NEON scalar floating-point absolute difference.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195803 91177308-0d34-0410-b5e6-96231b3b80d8