Rename some of the extern "C" C99 functions so we don't get infinite recursion.

Disabled long double testing when not available.

[SVN r45550]

libs/math

@@ -1 +1 @@
-Subproject commit b5520ad60b4d6400ab2e54339c1e5b0c17d9b5b6
+Subproject commit 211d58523cf5f191ccaf4817eac77e3e39357fb3