Fix std::isnan and friends for gcc2.

gcc2 was relying on the c99 functions being there, but they are not in
the std namespace.
* Disable the C99 functions and macros in C++ mode
* Redefine them as i

Fix std::isnan and friends for gcc2.

gcc2 was relying on the c99 functions being there, but they are not in
the std namespace.
* Disable the C99 functions and macros in C++ mode
* Redefine them as inline functions in cmath in the std namespace.

Fixes #7396.

show more ...

Renamed src/kernel to src/system.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12359 a95241bf-73f2-0310-859d-f6bbb57e9c96