PATCH [perl #112244]

:crlf currently doesn't fall back on :pending the way :perlio
does when the unread data doesn't fit into its own buffer. Instead it
just rejects them. This patch resolves that.  Tests are coming in a
future commit

The committer added a cast to get it to compile on Win32, and silence a
gcc warning on Linux
Some tests for [perl #112244]

Leon Timmermans is short of tuits right now, so I added these tests for
his patch.  Since I don't really know what I'm doing here, other tests
should eventually be added by someone who does know.
PATCH: [perl #116322]: getc() and ungetc() with unicode failure

ungetc() had no knowledge of UTF-8.  This patch adds it.

The committer fleshed out the author's code to make a patch, making
a few small changes.
Tests for [perl #116322]
dist/IO/IO.xs: Silence compiler warning

This variable is unused, doesn't need to be declared.