* decompress.c: Fix bugs with large buffers and weird inputs.

* decompress.c: Fix bugs with large buffers and weird inputs.

Tune a bit.  Reindent as per usual Emacs style.
(BUFFER_SIZE): Remove.
(Fdecompress_gzipped_region): Do not mishandle input buffers with
more than UINT_MAX bytes.  Decompress into the gap instead of into
an auto buffer, as this should avoid copying.  Return nil if
'inflate' returns Z_NEED_DICT, as we have no dictionary.  Do not
set immediate_quit; we shouldn't trust zlib code that much.