[DebugInfo/PDB] Adding getUndecoratedNameEx and IPDB interfaces for IDiaEnumTables and IDiaTable.

Initial changes to support debugging PE/COFF files with LLDB on Windows through DIA SDK.
There is another set of changes required on the LLDB side before this does anything.

Differential Revision: https://reviews.llvm.org/D39517

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318403 91177308-0d34-0410-b5e6-96231b3b80d8
19 files changed