A recent GDB change causes this test to fail due to missing RTTI for the
custom_cast type. This is presumably because the custom_cat type was
defined as a local class, so has no linkage. Moving it to local scope
seems to fix the test regressions, and probably makes the test more
realistic as a local class with no linkage isn't practical to use as an
error category that almost certainly needs to be referred to in other
scopes.
libstdc++-v3/ChangeLog:
* testsuite/libstdc++-prettyprinters/cxx11.cc: Move custom_cat
to namespace scope.
a8c7c3a409