Various feedstocks running into missing _availability_version_check

[h-vetinari]

Since the switch to clang 17, a few feedstocks seem to be running into errors that look like this:

Undefined symbols for architecture x86_64:
  "__availability_version_check", referenced from:
      ___isPlatformVersionAtLeast in libclang_rt.osx.a(os_version_check.c.o)
      __initializeAvailabilityCheck in libclang_rt.osx.a(os_version_check.c.o)

From looking for that symbol in the LLVM sources and looking at the recent changes, I'm presuming this has something to do with the following patch: llvm/llvm-project@b653a28

[h-vetinari]

OK, the revert of that patch in conda-forge/compiler-rt-feedstock#119 seems to have worked. Will probably have to raise an upstream issue.