[lworld] RFR: 8281471: [lworld] check_code.c should not accept Q-signatures as valid

[Harold Seigel]

Please review this small change to not allow Q signatures in old class files that are verified using the old verifier.  The change removes checks for Q signatures from the old verifier.

The fix was tested with Mach5 tiers 1-2 on Linux, Mac OS, and Windows, and Mach5 tiers 3-5 on Linux x64.

Thanks, Harold

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Commit messages:
 - 8281471: [lworld] check_code.c should not accept Q-signatures as valid

Changes: https://git.openjdk.java.net/valhalla/pull/645/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=645&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8281471
  Stats: 146 lines in 4 files changed: 131 ins; 3 del; 12 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/645.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/645/head:pull/645

PR: https://git.openjdk.java.net/valhalla/pull/645