All the declarations in math-finite.h are macroized by floating-point
type. This patch includes it for float128 and protects the
declarations of functions that need not be declared for float128.
* math/math.h: Include bits/math-finite.h for float128.
(__MATH_DECLARING_FLOATN): Define to control declaration of
float128 functions.
* math/bits/math-finite.h (pow10): Do not declare for float128.
(gamma): Likewise.
(scalb): Likewise.