RFR: 8361417: JVMCI getModifiers incorrect for inner classes

[Doug Simon]

The result of `ResolvedJavaType.getModifiers()` should always have been the same as `Class.getModifiers()`. This is currently not the case for inner classes. Instead, the value is derived from `Klass::_access_flags` where as it should be derived from the `InnerClasses` attribute (as it is for `Class`).

This PR aligns `ResolvedJavaType.getModifiers()` with `Class.getModifiers()`.

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Commit messages:
 - fix getModifiers() for inner classes

Changes: https://git.openjdk.org/jdk/pull/26135/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26135&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8361417
  Stats: 71 lines in 7 files changed: 36 ins; 20 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/26135.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26135/head:pull/26135

PR: https://git.openjdk.org/jdk/pull/26135