more on g++ regressions

[Jason Merrill]

>>>>> Joe Buck <jbuck@synopsys.com> writes:

> FAIL: g++.ext/pretty.C (test for excess errors)

> This test suggests that __PRETTY_FUNCTION__ is broken.

Using it as if it were a string no longer works.  Using it as a variable
still works.  I've fixed the tests.

Jason