[PATCH RFC] allow inline intrinsics for __ieee754_sqrt/f

[jon@beniston.com]

Hi Wilco,

>You could add more libm/machine/*/w_sqrt.c files.
>These already exist for arm and aarch64 - though they use 
>inline assembler rather than the obvious __builtin_sqrt. 

They don't get inlined like that though. So the idea is to move them from
there, in to the header, to allow them to be inlined, saving the call
overhead in sqrt().

>Note that the sqrt function will never be called if you have a sqrt
instruction (even if you forget to use -fno-math-errno), 

It will be from application code.

Cheers,
Jon