Ruby

Applied in changeset trunk|r61665.

zlib: reduce garbage on Zlib::GzipReader#readpartial

For garbage-concious users who use the outbuf' argument of readpartial' to supply a destination buffer, this provides
a drastic reduction in garbage when inflating large inputs
in a streaming fashion.

This results in a anonymous RSS reduction in the reader
similar to the reduction in the writer from r61631.

Results using the test script from r61631
https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=61631

Before:

 writer 7.359999 0.000000 7.359999 ( 7.360639) writer RssAnon: 4040 kB reader 6.346667 0.070000 6.416667 ( 7.387654) reader RssAnon: 98272 kB 

After:

 writer 7.309999 0.000000 7.309999 ( 7.310651) writer RssAnon: 4048 kB reader 6.146666 0.003333 6.149999 ( 7.334868) reader RssAnon: 4300 kB 

• ext/zlib/zlib.c (struct read_raw_arg): new struct
  (gzfile_read_raw_partial): use read_raw_arg
  (gzfile_read_raw_rescue): ditto
  (gzfile_read_raw): accept outbuf, use read_raw_arg
  (gzfile_read_raw_ensure): accept outbuf
  (gzfile_read_header): ditto
  (gzfile_check_footer): ditto
  (gzfile_read_more): ditto
  (gzfile_read_raw_until_zero): adjust for changes
  (gzfile_fill): ditto
  (gzfile_readpartial): ditto
  (gzfile_read_all): ditto
  (gzfile_getc): ditto
  (gzfile_reader_end_run): ditto
  (gzfile_reader_get_unused): ditto
  (rb_gzreader_initialize): ditto
  (gzreader_skip_linebreaks): ditto
  (gzreader_gets): ditto
  (zlib_gunzip_run): ditto
  [ruby-core:84660] [Feature #14319]