The termination function duplicated the functionality of the
attribute((destructor))-annotated function kmp_internal_end_fini,
and we have no indication that this doesn't work.
The function might cause issues with link-time optimization turned on:
until very recently, none of the usual linkers was reporting functions
named in -Wl,-fini as used to the LTO plugin, so it might be dropped.
If the function is dropped, -Wl,-fini=__kmp_internal_end_fini doesn't
do what we want: with ld.bfd and lld it drops the FINI attribute from
.dynamic and with gold we get FINI = 0x0, which leads to a crash on
cleanup. This can be reproduced by building with
-DLLVM_ENABLE_PROJECTS="clang;openmp" \ -DLLVM_ENABLE_LTO=Thin \ -DLLVM_USE_LINKER=gold
The issue in lld has been fixed in f95273f75aa, but gold remains without
fix so far.