RFR: 8337791: VectorAPI jtreg ABSMaskedByteMaxVectorTests crashes with UseAVXX=0 -XX:MaxVectorSize=8

[Jatin Bhateja]

This bug patch fixes a crash seen while querying the bottom type of MachTempNode corresponding to [rxmm0 operand](https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/x86/x86.ad#L22509) of blend pattern during late scheduling. Here, MaxVectorSize is contrainted to 8 bytes thus during C2 type system initialization, [TypeVect::VECTX ](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/type.cpp#L719) guarded by target supprted vector size remains uninitialized.

It better to reject matching of VectorBlend in such a scenario.

All exisitng VectorAPI jtreg tests are passing with -XX:UseAVX=0 and -XX:MaxVectorSize=8

Kindly review and share your feedback.

Best Regards,
Jatin

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Commit messages:
 - 8337791: VectorAPI jtreg ABSMaskedByteMaxVectorTests crash with UseAVX=0 -XX:MaxVectorSize=8

Changes: https://git.openjdk.org/jdk/pull/28533/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28533&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8337791
  Stats: 5 lines in 1 file changed: 5 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/28533.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28533/head:pull/28533

PR: https://git.openjdk.org/jdk/pull/28533