revert lex.ll parse.yy stdlib.ispc to state when all constants are floats

stdlib.ispc

@@ -1559,18 +1559,6 @@ static inline uniform float clamp(uniform float v, uniform float low, uniform fl
     return min(max(v, low), high);
 }
 
-// double
-
-__declspec(safe,cost2)
-static inline double clamp(double v, double low, double high) {
-    return min(max(v, low), high);
-}
-
-__declspec(safe,cost2)
-static inline uniform double clamp(uniform double v, uniform double low, uniform double high) {
-    return min(max(v, low), high);
-}
-
 // int8
 
 __declspec(safe,cost2)