RFR: 8277485: Zero: fix fast bytecodes implementation

[Jie Fu]

Hi all,

Please review the fix for zero fast bytecodes implementation.
The bug can be reproduced by building zero on x86_32.

Testing:
  - zero build on x86_{64,32}

Thanks.
Best regards,
Jie

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

Commit messages:
 - 8277485: Zero: fix fast bytecodes implementation

Changes: https://git.openjdk.java.net/jdk/pull/6479/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6479&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277485
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6479.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6479/head:pull/6479

PR: https://git.openjdk.java.net/jdk/pull/6479