PR middle-end/36757
* builtins.c (expand_builtin_signbit): Add asserts to make sure
we can expand BUILT_IN_SIGNBIT inline.
* builtins.def (BUILT_IN_SIGNBIT): Make type-generic.
* doc/extend.texi: Document the type-generic __builtin_signbit.
* c-common.c (check_builtin_function_arguments): Add check
for BUILT_IN_SIGNBIT argument.
* gcc.dg/builtins-error.c: Add checks for __builtin_signbit.
* gcc.dg/tg-tests.h: Add checks for __builtin_signbit.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@226990 138bc75d-0d04-0410-961f-82ee72b054a4