RFR: 8347346: Remove redundant ClassForName.java and test.policy from runtime/Dictionary

[Kevin Walls]

Redundant files in test/hotspot/jtreg/runtime/Dictionary, ClassForName.java and test.policy

Left over after SM removal tasks:
8341916: Remove ProtectionDomain related hotspot code and tests

ClassForName.java was built by test/hotspot/jtreg/runtime/Dictionary/ProtectionDomainCacheTest.java

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Commit messages:
 - Remove ClassForName.java
 - Remove test.policy

Changes: https://git.openjdk.org/jdk/pull/23005/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23005&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347346
  Stats: 53 lines in 2 files changed: 0 ins; 53 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23005.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23005/head:pull/23005

PR: https://git.openjdk.org/jdk/pull/23005