Revert "Recommitted r261634 "Supporting all entities declared in lexical scope in LLVM debug info." After fixing PR26715 at r263379."

This reverts commit r263425. Breaks self-host.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@263436 91177308-0d34-0410-b5e6-96231b3b80d8