[Committed] Fix C++/29295, wrong code with typedef of Bools

[Andrew Pinski <pinskia at gmail dot com>]

The problem here is that the C++ front-end is comparing the pointer
value of a type to boolean_type_node instead of using same_type_p so we
produce wrong code (and accept invalid code) with typedefs in some
places.  Anyways this patch fixes the problem by replacing the pointer
comparision with a call to same_type_p.

Applied as obvious to the mainline, this is not a regression as far as I
can tell, it was broken in 2.95.3 and above and looks like the code has
been always wrong.  I did bootstrap/test on i686-linux-gnu with no
regressions.

Thanks,
Andrew Pinski

cp/ChangeLog:

	* typeck.c (build_unary_op): Use same_type_p when comparing to 
	boolean type.

testsuite/ChangeLog:

	* g++.dg/expr/bool1.C: New test.
	* g++.dg/expr/bool2.C: New test.

Index: testsuite/g++.dg/expr/bool1.C
===================================================================
--- testsuite/g++.dg/expr/bool1.C	(revision 0)
+++ testsuite/g++.dg/expr/bool1.C	(revision 0)
@@ -0,0 +1,21 @@
+// { dg-do run }
+// PR C++/29295
+// make sure that a typedef for a bool will have the
+//  the same results as a bool itself.
+
+extern "C" void abort();
+typedef bool my_bool;
+int main()
+{ 
+  my_bool b = false;
+  int i;
+
+  b++;
+  b++;
+  i = b;
+  if (i != 1)
+    abort ();
+  return 0;
+}
+
+
Index: testsuite/g++.dg/expr/bool2.C
===================================================================
--- testsuite/g++.dg/expr/bool2.C	(revision 0)
+++ testsuite/g++.dg/expr/bool2.C	(revision 0)
@@ -0,0 +1,13 @@
+// { dg-do compile }
+// make sure that a typedef for a bool will have the
+//  the same results as a bool itself.
+
+
+typedef bool my_bool;
+int main()
+{
+  my_bool b = false;
+  b--; // { dg-error "" }
+  return 0;
+}
+
Index: cp/typeck.c
===================================================================
--- cp/typeck.c	(revision 118112)
+++ cp/typeck.c	(working copy)
@@ -4192,7 +4192,7 @@ build_unary_op (enum tree_code code, tre
 	  return error_mark_node;
 
 	/* Forbid using -- on `bool'.  */
-	if (TREE_TYPE (arg) == boolean_type_node)
+	if (same_type_p (TREE_TYPE (arg), boolean_type_node))
 	  {
 	    if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
 	      {