Update GCC revision in tools/REVISIONS
Update GCC revision in tools/REVISIONS

This brings in:

ea8b744 Use 'ud2' assembly mnemonic instead of assembling the opcode as data

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3792
TEST= toolchain trybots
R=sehr@chromium.org, mseaborn@chromium.org

Review URL: https://codereview.chromium.org/166763003

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@12787 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client