13.0.1-rc2 release update


There have been some buildbot failures in the release/13.x branch, so
I'm going to delay -rc2 until Thursday to investigate.


I've updated OpenMandriva packaging to current 13.x branch to get a preview of 13.0-rc2 (I presume it's 13.0.0-rc2, not 13.0.1?).

Overall, aside from the issues mentioned for rc1 (new-ish components like MLIR, flang, libc failing to build) mostly looks good. We found one more regression in 13.0-rc2 (compared to 12.x - this was also in rc1, just went unnoticed) affecting PGO.

Doing something along the lines of
export LLVM_PROFILE_FILE=xyz-%p.profile.d
export CFLAGS="-O2 -fprofile-instr-generate"
export CXXFLAGS="-O2 -fprofile-instr-generate"
# Run the generated binaries in some expected ways, e.g. "make check"
llvm-profdata merge --output=xyz.profile xyz-*.profile.d

consistently (obviously with PIDs varying) results in
warning: xyz-670250.profile.d: malformed instrumentation profile data
warning: xyz-670257.profile.d: malformed instrumentation profile data
error: no profile can be merged

The *.profile.d files look ok at a first glance, and "file" recognizes them as "LLVM raw profile data, version 7".

Looks like only "llvm-profdata merge" is broken, using -fprofile-instr-use=<any of the individual files> seems to be ok.
Will file a bug report...



I have changed the raw profile format which resulted in issues in llvm-profdata merge and fixed in later commits.
Could we please cherry-pick the commits into the release/13.0.0 branch which are reported in the following tickets: