Summary:
These functions provide special-case implementations internal to the
OpenMP device runtime. This can potentially conflict with the symbols
pulled in from the actual GPU `libc`. This patch makes these weak, so in
the case that the GPU libc functions exist they will be overridden. This
should not impact performance in the average case because the old
`-mlink-builtin-bitcode` version does internalization, deleting weak,
and the new LTO path will resolve to the strong reference and then
internalize it.
3c50cbfda4