RFR: 8343693: [JVMCI] Override ModifiersProvider.isConcrete in ResolvedJavaType to be isArray() || !isAbstract()

[Yudi Zheng]

The `isArray() || !isAbstract()` idiom is often used in Graal for expressing if a type is concrete and can have its instance. This PR overrides `ModifiersProvider.isConcrete` in `ResolvedJavaType` to provide this idiom.

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Commit messages:
 - Override ModifiersProvider.isConcrete in ResolvedJavaType

Changes: https://git.openjdk.org/jdk/pull/22111/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22111&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343693
  Stats: 8 lines in 2 files changed: 5 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/22111.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22111/head:pull/22111

PR: https://git.openjdk.org/jdk/pull/22111