[PATCH] Fix type safeness in C++ front-end and dynamic_cast

[Andrew Pinski <pinskia at physics dot uc dot edu>]

The problem here is that the types in a compare between a pointer
and null when generating it for a dynamic_cast.
This patch fixes that problem by calling cp_convert on the
integer_zero_cst.

OK? Bootstrapped and tested on ppc-darwin with no regressions.

Thanks,
Andrew Pinski

ChangeLog:
	* rtti.c (ifnonnull): Cast the zero comparison operand
	to the correct type.

Patch:

Attachment: t.diff.txt
Description: Text document

Testcase:
// { dg-do compile }
// { dg-options "-O2" }
// We used to ICE in compare_values as the types for a comparison
// we not the same kind of types.
struct class1
{
  virtual ~class1 ();
};
struct class2 :  class1 { };

void f(class1 * oo)
{
  class2 * oj = dynamic_cast <class2 *>(oo) ;
  if (oj)
    delete oo;
}