RFR: 8373724: Assertion failure in TestSignumVector.java with UseAPX

[Jatin Bhateja]

Existing demotable instruction patterns for negI/L_rReg_ndd have 'src' as their second operand, this leads to an failure during register biasing. Changing the NDD demotion flags names to encode explicit operand position i.e. **Flag_ndd_demotable_opr1 and Flag_ndd_demotable_opr2** , splitting commutative flag into seperate new flags and fine tuning assertion checks based on new naming convention fixes the issue.

Failing test test/hotspot/jtreg/compiler/vectorization/TestSignumVector.java passes with the patch.

Kindly review and share your feedback.

Best Regards,
Jatin
PS: Validation performed using Intel SDE 9.58.

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Commit messages:
 - 8373724: Assertion failure in TestSignumVector.java with UseAPX

Changes: https://git.openjdk.org/jdk/pull/28999/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28999&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8373724
  Stats: 74 lines in 1 file changed: 0 ins; 0 del; 74 mod
  Patch: https://git.openjdk.org/jdk/pull/28999.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28999/head:pull/28999

PR: https://git.openjdk.org/jdk/pull/28999