devel/llvm12: Update to 12.0.1 release

This release restores Reporter.py required for scan-build. [0]

Correct missing renames of lit modules. [1]

Remove no-op LLD_LINK option.

PR: 256297 [0], 257123 [1]
Reported by: phk [0], Derek Schrock <dereks@lifeofadishwasher.com> [1]