RFR: 8292202: modules_do is called without Module_lock

[Calvin Cheung]

Please review this fix which involves:

- acquire the `Module_lock` before calling `modules_do`;
- move the call to `ClassLoader::setup_module_search_path `out of `do_module`;
- save the module paths in a `GrowableArray` in `do_module` for calling `ClassLoader::setup_module_search_path`.

Passed tiers 1 - 3 testing.

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Commit messages:
 - 8292202: modules_do is called without Module_lock

Changes: https://git.openjdk.org/jdk/pull/10291/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10291&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8292202
  Stats: 20 lines in 1 file changed: 15 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/10291.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10291/head:pull/10291

PR: https://git.openjdk.org/jdk/pull/10291