RFR: 8292596: Make SymbolHashMap a ResourceHashtable [v4]

[Coleen Phillimore]

> Please review this straightforward change to use ResourceHashtable for SymbolHashMap, which is used by the Class File Reconstituter.  The table maps Symbol* to constant pool indices for loaded classes (Symbol refcounting unnecessary as the class is not unloaded because it's in use).
> Tested with jvmti tests locally and tier 1-3.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Hide SymbolHash inside of ConstantPool so people don't get the wrong idea about it.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/9917/files
  - new: https://git.openjdk.org/jdk/pull/9917/files/da82d26c..7f3d9c24

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9917&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9917&range=02-03

  Stats: 44 lines in 4 files changed: 16 ins; 17 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/9917.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9917/head:pull/9917

PR: https://git.openjdk.org/jdk/pull/9917