Revert "Reapply "DebugInfo: Ensure that all debug location scope chains from...

Revert "Reapply "DebugInfo: Ensure that all debug location scope chains from instructions within a function, lead to the function itself.""

This reverts commit r214761.

Revert while Reid investigates & provides a reproduction for an
assertion failure for this on Windows.

llvm-svn: 214999