_GL_HAS_BUILTIN_OVERFLOW_P  127 lib/intprops-internal.h #    define _GL_HAS_BUILTIN_OVERFLOW_P 0
_GL_HAS_BUILTIN_OVERFLOW_P  129 lib/intprops-internal.h #    define _GL_HAS_BUILTIN_OVERFLOW_P __has_builtin (__builtin_mul_overflow_p)
_GL_HAS_BUILTIN_OVERFLOW_P  131 lib/intprops-internal.h #    define _GL_HAS_BUILTIN_OVERFLOW_P (7 <= __GNUC__)