[Debug Info] unique MDNodes in the enum types of each compile unit.

The enum types array by design contains pointers to MDNodes rather than DIRefs.
Unique them when handling the enum types in DwarfDebug.

rdar://17628609


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214139 91177308-0d34-0410-b5e6-96231b3b80d8
Clean up testing cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214142 91177308-0d34-0410-b5e6-96231b3b80d8
Tweak llvm-nm’s -undefined-only (aka -u) printing for Mach-O files
to just print the symbol name.  So it matches darwin’s nm(1) -u option.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214143 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-uselistorder: Add -num-shuffles option

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214144 91177308-0d34-0410-b5e6-96231b3b80d8