PATCH: Tidy C++ testsuite

[Neil Booth]

Mark Mitchell wrote:-

> Some time ago, we made the G++ testsuite start ignoring "instantiated
> from here" error lines since they change around with small perturbations
> in the compiler.

I imagine this kind of issue would vanish with a proper parser 8-)
I can't wait to get rid of c-parse.in; it causes so much unnecessary
baggage, and prevents other "good stuff" 8-)

Neil.