Fixed regressions with "Patch: Remove input_file_stack"

[Tom Tromey]

>>>>> "Hans-Peter" == Hans-Peter Nilsson <hans-peter.nilsson@axis.com> writes:

Hans-Peter> I'm a bit surprised your testing didn't show these fallout
Hans-Peter> regressions (for cris-elf, but I see from gcc-testresults@ the
Hans-Peter> same new FAILs, your patch being the only suspect in the range
Hans-Peter> 132770:132776):

Me too.  Sorry about that.

Hans-Peter> I committed the following as obvious.  This exact construct was
Hans-Peter> in other libstdc++ tests.

Thank you.

Tom