Don't inline fenv.h functions on arm for now. Inlining makes sense:
the function bodies require only 2 to 10 instructions. However, it
leads to application binaries that refer to a private ABI, namely, the
softfloat innards in libc. This could complicate future changes in
the implementation of the floating-point emulation layer, so it seems
best to have programs refer to the official fe* entry points in libm.