print-rtl: NOT is ~, not !

Slim RTL dumps print the RTL code NOT as !, but that is misleading:
its semantics are like the C operator ~.  This fixes it.


	* print-rtl.c (print_exp): Print NOT as "~" instead of as "!".

From-SVN: r250913

gcc/ChangeLog

+2017-08-07  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	* print-rtl.c (print_exp): Print NOT as "~" instead of as "!".
+
 2017-08-07  Marek Polacek  <polacek@redhat.com>
 
 	PR middle-end/81737

gcc/print-rtl.c

@@ -1283,7 +1283,7 @@ print_exp (pretty_printer *pp, const_rtx x, int verbose)
       op[1] = XEXP (x, 1);
       break;
     case NOT:
-      st[0] = "!";
+      st[0] = "~";
       op[0] = XEXP (x, 0);
       break;
     case AND: