Resubmitting UCN patch

Attached again is my patch (unaltered) and new test files.
I'm not sure which directory to add them to at the moment, so simply
submitted as cpp files.

Following advice, I have split out the passing and xfail tests into separate
files.
I could trim this set further by taking out the tests for incomplete UCNs as
that was part of feature-coverage for [lex.charset]p2, rather than something
specific to n2170.

I have dropped the C test file as I'm still waiting guidance on where this
goes - I will then look into similar files and submit a more appropriate
test. Essentially, this is simply testing the 'extension' warning for UCNs
in C90 code so should not be critical to patch acceptance.

I would still like to add the full XFAILed [lex.charset]p2 test as well, but
I'll see where we think the current tests belong first.

AlisdairM

n2170.patch (2.02 KB)

n2170.cpp (1.18 KB)

n2170_xfail.cpp (6.93 KB)