compiler-rt: fix logic for choosing `__gnu_{f2h,h2f}_ieee`

wasm32-wasi-musl wants the standard symbol names however Linux requires
the `__gnu_*` flavors. I did not find any authoritative source on what
decides which symbol flavors to use. If we run into more trouble in the
future we can go back to having both.
30ef033693Andrew Kelley committed on 6/18/2022, 3:25:17 AMparente4092d4
3 files changedLine totals unavailable