lang/rust: unbreak on aarch64 after r459911

gmake: Leaving directory '.../aarch64-unknown-freebsd/release/build/rustc_binaryen-cfb76adb9420e94c/out/build'

• stderr

c++: error: the clang compiler does not support '-march=native'
c++: error: the clang compiler does not support '-march=native'

PR: 225600
Reported by: Gergely Czuczy, pkg-fallout
Obtained from: upstream (binaryen 1.37.35)
Approved by: portmgr blanket