redundant namespacing of standard c functions

[coypu%sdf.org@localhost]

Hi,

we produce suboptimal code because e.g. isinf and isnan are namespace
guarded, we define a __isnan instead, and use macros to rename.
this disallows compilers from optimizing the function with a builtin,
which saves at least the function call.

can we as a policy have symbols for all the standard C things
(weakref'd)?