RFR: 8367259: Clean up make/scripts and bin directory

Tue Sep 9 14:39:28 UTC 2025

Over time, cruft have accumulated in terms of scripts that are no longer relevant. These should be removed. Also, scripts that are not used as part of the build process, but run by JDK developers from time to time, should reside in `bin` instead of `make/scripts`.

I have also updated `generate-symbol-data.sh` and `update_pch.sh` so they work regardless of current dir.

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Commit messages:
 - 8367259: Clean up make/scripts and bin directory

Changes: https://git.openjdk.org/jdk/pull/27172/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27172&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367259
  Stats: 657 lines in 11 files changed: 113 ins; 540 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/27172.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27172/head:pull/27172

PR: https://git.openjdk.org/jdk/pull/27172