libstdc++/7680: float functions undefined in math.h/cmath with #define _XOPEN_SOURCE

[ljrittle@gcc.gnu.org]

Synopsis: float functions undefined in math.h/cmath with #define _XOPEN_SOURCE

State-Changed-From-To: open->closed
State-Changed-By: ljrittle
State-Changed-When: Tue Apr 15 09:33:40 2003
State-Changed-Why:
    Patch applied to 3.3 branch.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7680