Define metadata interfaces for describing a static data member
of a class. Emit static data member declarations and definitions
through correctly.

Part of PR14471.

Patch by Paul Robinson!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172590 91177308-0d34-0410-b5e6-96231b3b80d8
reverting 172579

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172594 91177308-0d34-0410-b5e6-96231b3b80d8