RFR: 8284549: JFR: FieldTable leaks FieldInfoTable member [v2]

[Zhengyu Gu]

> `FieldTable` is a `ResourceObj` and it has a member points to `FieldInfoTable`, which is a `CHeapObj`.
> 
> Since ResouceObj's destructor is never called, so it can not depend on `FieldTable`s destructor to  free `FieldInfoTable`, it needs to be freed explicitly.

Zhengyu Gu has updated the pull request incrementally with one additional commit since the last revision:

  Thomas' comment

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8149/files
  - new: https://git.openjdk.java.net/jdk/pull/8149/files/59f86653..4f29ddca

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8149&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8149&range=00-01

  Stats: 16 lines in 1 file changed: 10 ins; 5 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8149.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8149/head:pull/8149

PR: https://git.openjdk.java.net/jdk/pull/8149