[jdk11u-dev] RFR: 7131823: bug in GIFImageReader

[Dan Lutker]

This is a backport of JDK-7131823: bug in GIFImageReader

Original patch applied cleanly and all imageio tests pass on linux x64 including the new `javax/imageio/plugins/gif/GIFLargeTableIndexTest.java`.

Summary: jdk_imageio
TEST STATS: name=jdk_imageio  run=196  pass=196  fail=0


All teir1 passed as well.

==============================
Test summary
==============================
   TEST                                              TOTAL  PASS  FAIL ERROR   
   jtreg:test/hotspot/jtreg:tier1                     1461  1461     0     0   
   jtreg:test/jdk:tier1                               1874  1874     0     0   
   jtreg:test/langtools:tier1                         3924  3924     0     0   
   jtreg:test/nashorn:tier1                              0     0     0     0   
   jtreg:test/jaxp:tier1                                 0     0     0     0   
==============================
TEST SUCCESS

-------------

Commit messages:
 - Backport a31130fd4056907edcb420761722c629a33273eb

Changes: https://git.openjdk.org/jdk11u-dev/pull/1317/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1317&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-7131823
  Stats: 175 lines in 2 files changed: 158 ins; 4 del; 13 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1317.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1317/head:pull/1317

PR: https://git.openjdk.org/jdk11u-dev/pull/1317