Bugfix for making the DWARF debug strings and labels to code emitted as secrel32 instead of long opcodes (only for coff). This makes them debuggable with GDB.

fixes Bug 16249 - LLVM generates broken debug info on Windows 

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187597 91177308-0d34-0410-b5e6-96231b3b80d8