Add "#cmakedefine" to pyconfig.h.in erroneously omitted.

In 9baa8f2fc, the #cmakedefine associated with "acosh", "isfinite", "isinf",
"isnan", "tgamma" and "tanh_preserves_zero_sign" have been omitted.
This commit fixes it.
Merge branch 'add-missing-cmakedefine' into next

* add-missing-cmakedefine:
  Add "#cmakedefine" to pyconfig.h.in erroneously omitted.