RFR: 8270184: [TESTBUG] Add coverage for jvmci ResolvedJavaType.toJavaName() for lambdas

[Severin Gehwolf]

Please review this simple test addition. It adds more coverage `toJavaName()` for generated classes for lambdas.

Testing: jtreg:test/hotspot/jtreg/compiler/jvmci

Thoughts?

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Commit messages:
 - 8270184: [TESTBUG] Add coverage for jvmci ResolvedJavaType.toJavaName() for lambdas

Changes: https://git.openjdk.java.net/jdk/pull/4746/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4746&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8270184
  Stats: 13 lines in 1 file changed: 13 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4746.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4746/head:pull/4746

PR: https://git.openjdk.java.net/jdk/pull/4746