-------------------------
	Fix the crossDllArg crash
	-------------------------

Test codeGen/should_compile/cg004 tests for this one.  The problem was
that the test for static-ness (i.e. no need to CAFify the thing) encountered
a form we didn't previously expect.  (See cg004)

This fix tidies up CoreUtils.rhsIsNonUpd, which is the original entry point,
renaming it CoreUtils.hasNoRedexes