[PATCH] Introduce --enable-math-noprivate

[Wilco Dijkstra]

Hi Florian,

My question is, would a new config option really be useful? Errno can be set
outside the critical paths, so inlining it doesn't help at all. Therefore this should
be done by default.

Similarly the strtod_nan* dependency seems worthwhile to remove too.
If these are the main dependencies between libc and libm, I can't see
the value of adding a new config option.

Wilco