RFR: 8371133: Clarify the purpose of "src/jdk.compiler/share/classes/com/sun/tools/javac/resources/ct.properties" [v2]

[Volkan Yazici]

> Document usage and purpose of `ct.properties`.

Volkan Yazici has updated the pull request incrementally with one additional commit since the last revision:

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Changes:
  - all: https://git.openjdk.org/jdk/pull/28123/files
  - new: https://git.openjdk.org/jdk/pull/28123/files/9edb525a..476a98d3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28123&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28123&range=00-01

  Stats: 8 lines in 1 file changed: 4 ins; 3 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/28123.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28123/head:pull/28123

PR: https://git.openjdk.org/jdk/pull/28123