[PATCH] support: Define support_static_assert for use from C and C++

[Paul Eggert]

Florian Weimer wrote:
> _Static_assert is reserved in C++ as well, so I don't want to touch it. The GCC 
> headers might eventually use it in a way which is not strictly equivalent to 
> static_assert.

If we don't care about the difference (what is it, by the way?), then something 
like this should work:

#ifndef __cplusplus
# define static_assert _Static_assert
#endif

since "static_assert" is not reserved in C.

I wish these committees would coordinate better....