Remove builtins hack

Author: antoyo

src/context.rs

@@ -226,21 +226,6 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             /*"__builtin_sadd_overflow",*/
             "__builtin_smulll_overflow", /*"__builtin_smul_overflow",*/
             "__builtin_ssubll_overflow",
-            /*"__builtin_ssub_overflow",*/ "__builtin_sub_overflow",
-            "__builtin_uaddll_overflow",
-            "__builtin_uadd_overflow",
-            "__builtin_umulll_overflow",
-            "__builtin_umul_overflow",
-            "__builtin_usubll_overflow",
-            "__builtin_usub_overflow",
-            "__builtin_powif",
-            "__builtin_powi",
-            "fabsf",
-            "fabs",
-            "copysignf",
-            "copysign",
-            "nearbyintf",
-            "nearbyint",
         ];
 
         for builtin in builtins.iter() {