meson is detecting it does not support 64bit attomics but then when
defining local suppliments confused clang
../mesa-19.3.1/src/util/u_atomic.c:38:1: error: cannot redeclare builtin function '__sync_add_and_fetch_8'
__sync_add_and_fetch_8(uint64_t *ptr, uint64_t val)
^
../mesa-19.3.1/src/util/u_atomic.c:38:1: note: '__sync_add_and_fetch_8' is a builtin with type 'long long (volatile long long *, long long, ...)'
../mesa-19.3.1/src/util/u_atomic.c:38:1: error: definition of builtin function '__sync_add_and_fetch_8'
__sync_add_and_fetch_8(uint64_t *ptr, uint64_t val)
^
Signed-off-by: Khem Raj <raj.khem@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>