[Committed] Update g++.dg/other/pr84964.C for ia32 (and similar) targets.

[Committed] Update g++.dg/other/pr84964.C for ia32 (and similar) targets.

The "sorry, unimplemented" message in the new g++.dg/other/pr84964.C is
apparently dependent upon whether the target passes multi-gigabyte
arguments on the stack.  This tweaks the testcase to just confirm that
it no longer ICEs, not the specific set of warnings/errors triggered.

2022-03-11  Roger Sayle  <roger@nextmovesoftware.com>

gcc/testsuite/ChangeLog
	PR c++/84964
	* g++.dg/other/pr84964.C: Tweak test to check for the ICE, not for
	the (target-dependent) sorry.