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

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

This reverts commit r212205.

Reverting this again, still seeing crashes when building compiler-rt...
Sorry for the continued noise, not sure why I'm failing to reproduce
this locally.

llvm-svn: 212226