Use `@static if` in `CompilerSupportLibraries_jll.__init__()` (#61516)
Hopefully enough to fix JuliaC on `aarch64-linux`
(https://buildkite.com/julialang/julia-master/builds/56266#019d6367-fc8d-4806-a1f1-00ec67370c77/L1315-L1319):
```
Error #2: unresolved call from statement string(
getproperty(
libquadmath::Any,
:path::Symbol
)::Any
)::Any
Stacktrace:
[1] __init__()
@ CompilerSupportLibraries_jll ./CompilerSupportLibraries_jll/src/CompilerSupportLibraries_jll.jl:158
```