RFR: 8364226: Better ECDSASignature Memory Management [v3]

[Kevin Driver]

> Enhance the memory management/cleanup for `ECDSASignature`.

Kevin Driver has updated the pull request incrementally with one additional commit since the last revision:

  remove whitespace differences

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26516/files
  - new: https://git.openjdk.org/jdk/pull/26516/files/2cfaefcd..76ed979e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26516&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26516&range=01-02

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/26516.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26516/head:pull/26516

PR: https://git.openjdk.org/jdk/pull/26516