Remove constant handling from fold_builtin_{,f}abs

fold_builtin_fabs and fold_builtin_abs had code to handle constant
arguments, but this simply duplicated what the following fold_build1_loc
would do for ABS_EXPR.

Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi.

gcc/
	* builtins.c (fold_builtin_fabs): Remove constant handling.
	(fold_builtin_abs): Likewise.

From-SVN: r229427

gcc/ChangeLog

 2015-10-27  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* builtins.c (fold_builtin_fabs): Remove constant handling.
+	(fold_builtin_abs): Likewise.
+
+2015-10-27  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* builtins.c (fold_builtin_copysign): Delete.
 	(fold_builtin_2): Handle constant copysign arguments here.
 	* match.pd: Add rules previously handled by fold_builtin_copysign.

gcc/builtins.c

@@ -7847,8 +7847,6 @@ fold_builtin_fabs (location_t loc, tree arg, tree type)
     return NULL_TREE;
 
   arg = fold_convert_loc (loc, type, arg);
-  if (TREE_CODE (arg) == REAL_CST)
-    return fold_abs_const (arg, type);
   return fold_build1_loc (loc, ABS_EXPR, type, arg);
 }
 
@@ -7861,8 +7859,6 @@ fold_builtin_abs (location_t loc, tree arg, tree type)
     return NULL_TREE;
 
   arg = fold_convert_loc (loc, type, arg);
-  if (TREE_CODE (arg) == INTEGER_CST)
-    return fold_abs_const (arg, type);
   return fold_build1_loc (loc, ABS_EXPR, type, arg);
 }