[Assignment Tracking][25/*] Replace sunk address uses in dbg.assign intrinsics

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

Reviewed By: StephenTozer

Differential Revision: https://reviews.llvm.org/D136255