`libomp` uses `__builtin_return_address` in two places. However, on some
targets those calls need to wrapped in `___builtin_extract_return_addr`
to get at the actual return address. SPARC is among those targets and
the only one where `clang` actually implements this, cf. [[clang][Sparc]
Fix __builtin_extract_return_addr
etc.](https://reviews.llvm.org/D91607). `compiler-rt` needed the same
adjustment, cf. [[sanitizer_common][test] Enable tests on
SPARC](https://reviews.llvm.org/D91608). On other targets, this is a
no-op. However, there are more targets that have the same issue and
`gcc`, unlike `clang`, correctly implements it, so there might be issues
when building `libomp` with `gcc`.
This patch adds the necessary calls.
Tested on `sparcv9-sun-solaris2.11`, `sparc64-unknown-linux-gnu`,
`amd64-pc-solaris2.11`, and `x86_64-pc-linux-gnu`.
a2a280e58c