Error: non-private labels cannot appear between .cfi_startproc / .cfi_endproc pairs

[Knapoc]

Trying to compile gcc13, clang-17 and others using Apple clang version 16.0.0 (clang-1600.0.26.3) provided by Xcode, the following error is thrown:

<instantiation>:5:1: error: non-private labels cannot appear between .cfi_startproc / .cfi_endproc pairs
___aarch64_cas1_relax:
^
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_gcc13/gcc13/work/gcc-13.3.0/libgcc/config/aarch64/lse.S:220:1: note: while in macro instantiation
STARTFN __aarch64_cas1_relax
^
<instantiation>:4:2: error: previous .cfi_startproc was here
 .cfi_startproc
 ^
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_gcc13/gcc13/work/gcc-13.3.0/libgcc/config/aarch64/lse.S:220:1: note: while in macro instantiation
STARTFN __aarch64_cas1_relax
^

Tickets on macports (check these for more detailed log files):

• gcc13: https://trac.macports.org/ticket/70710
• clang17: https://trac.macports.org/ticket/70779

It seems llvm itself phased similar issues in the past:

• Mach-O check for improperly nested .cfi_* regions doesn't take .alt_entry into account llvm/llvm-project#97116
• https://reviews.llvm.org/D155245#4657375

The fix provided in llvm#97479 was back ported back in July, but in a different manner:
94471e7