RFR: 8324667: fold Parse::seems_stable_comparison() [v2]

[Joshua Cao]

> The function has a long comment block that seems irrelevant since https://github.com/openjdk/jdk/commit/8bd4b5624c6ece31d965259aadc290a24d44423a. We can just fold away this method. It only has one caller.
> 
> 
> passes GHA

Joshua Cao has updated the pull request incrementally with two additional commits since the last revision:

 - Update copyright for parse.hpp
 - Remove seems_stable_comparison() from header and remove copyright

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/17573/files
  - new: https://git.openjdk.org/jdk/pull/17573/files/42943fd5..a7884324

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17573&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17573&range=00-01

  Stats: 3 lines in 2 files changed: 0 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17573.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17573/head:pull/17573

PR: https://git.openjdk.org/jdk/pull/17573