[zlib] Re-sync with zlib 1.2.12, patch 4 of N

Ported:
- Small speedup to inflate [psumbera]

It seems to be around +1% improvement in decompression:
adenilson@Adenilsons-Air tot % ./zlib_bench gzip ~/corpus/flex/*
/Users/adenilson/corpus/flex/baddata1.snappy :
GZIP: [b 1M] bytes  27512 ->  22920 83.31% comp  66.8 ( 67.1) MB/s uncomp 234.0 (235.6) MB/s
/Users/adenilson/corpus/flex/geo.protodata :
GZIP: [b 1M] bytes 118588 ->  15124 12.75% comp 154.4 (154.7) MB/s uncomp 1310.5 (1311.6) MB/s
/Users/adenilson/corpus/flex/html_x_4    :
GZIP: [b 1M] bytes 409600 ->  53285 13.01% comp 107.2 (107.4) MB/s uncomp 1174.3 (1179.1) MB/s
/Users/adenilson/corpus/js-data.txt      :
GZIP: [b 1M] bytes 122903539 -> 37369556 30.41% comp  46.1 ( 46.1) MB/s uncomp 562.6 (563.2) MB/s
/Users/adenilson/corpus/linux-5.6-rc3.tar :
GZIP: [b 1M] bytes 957450240 -> 180809431 18.88% comp  61.1 ( 61.5) MB/s uncomp 738.0 (747.2) MB/s

adenilson@Adenilsons-Air psumbera % ./zlib_bench gzip ~/corpus/flex/*
/Users/adenilson/corpus/flex/baddata1.snappy :
GZIP: [b 1M] bytes  27512 ->  22920 83.31% comp  66.0 ( 66.6) MB/s uncomp 236.7 (239.2) MB/s
/Users/adenilson/corpus/flex/geo.protodata :
GZIP: [b 1M] bytes 118588 ->  15124 12.75% comp 154.6 (154.8) MB/s uncomp 1322.3 (1328.8) MB/s
/Users/adenilson/corpus/flex/html_x_4    :
GZIP: [b 1M] bytes 409600 ->  53285 13.01% comp 107.3 (107.5) MB/s uncomp 1185.4 (1187.1) MB/s
/Users/adenilson/corpus/js-data.txt      :
GZIP: [b 1M] bytes 122903539 -> 37369556 30.41% comp  46.0 ( 46.1) MB/s uncomp 565.4 (566.0) MB/s
/Users/adenilson/corpus/linux-5.6-rc3.tar :
GZIP: [b 1M] bytes 957450240 -> 180809431 18.88% comp  61.5 ( 62.1) MB/s uncomp 749.9 (836.4) MB/s

Bug: 1032721
Change-Id: Iabf6f5c5cc94a4e8219c22831246cd353ddc7d23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3563969


Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/main@{#987687}
NOKEYCHECK=True
GitOrigin-RevId: 0eadcbc195a56d05635dd35feb4ee4cd72abe161