llvm-project

87d69410 - Reverting PR #184065 and #200323 to address some interplay with CFI (#201194)

Reverting PR #184065 and #200323 to address some interplay with CFI (#201194) There is a relation between CFI and ThinLTO GUIDs that still needs to be disentangled first. Note that we leave the `MD_unique_id` in `FixedMetadataKinds.def` to avoid needing to re-number it later. Plus the metadata string ("guid") itself is used by ctxprof.