The Assignment Tracking debug-info feature is outlined in this RFC:
https://discourse.llvm.org/t/
rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir
This test covers the NFC-for-normal-debug-info change D133303.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D133319
OCHyams