Revert of D49126 [PredicateInfo] Use custom mangling to support ssa_copy with unnamed...

Revert of D49126 [PredicateInfo] Use custom mangling to support ssa_copy with unnamed types.

Now that intrinsic name mangling can cope with unnamed types, the custom name mangling in PredicateInfo (introduced by D49126) can be removed.
(See D91250, D48541)

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D91661