The change is fairly mechanical:
1. Factor code from `FastISel::selectIntrinsicCall`, which converts
debug intrinsics into debug instructions, into functions (NFC).
2. Call those functions for DPValues attached to instructions too.
The test updates look the same as other RemoveDIs changes: re-run the
tests with `--try-experimental-debuginfo-iterators`, which checks the
output is identical using the new debug info format (if it has been
enabled in the cmake configuration).
Depends on #76941 (otherwise some modified tests spuriously fail).
This test is XFAIL'd on most arches, and seems too fragile to be run on non-X86.
Reviewed By: jmorse, probinson
Differential Revision: https://reviews.llvm.org/D109806
