Patch to simple_cst_equal

[Jeffrey A Law]

  In message < 199807270802.BAA05250@yorick.cygnus.com >you write:
  > This is necessary to support a fix for a serious C++ bug; a "function-style
  > cast" A() is supposed to create a temporary A initialized to 0.  I've
  > implemented this by initializing it with an empty CONSTRUCTOR, but if that
  > gets back to simple_cst_equal, we have a problem.
  > 
  > This fix is pretty simplistic, but it gets the job done.
  > 
  > Mon Jul 27 00:54:41 1998  Jason Merrill  <jason@yorick.cygnus.com>
  > 
  > 	* tree.c (simple_cst_equal, case CONSTRUCTOR): OK if the elts are
  > 	identical.
Seems reasonable to me.  Can you install it into the main sources
and the branch?

Thanks,
jeff