RFR: JDK-8264488: Improve warning for module names ending with digits [v2]

[Sebastian Stenzel]

> Since this is a rather trivial change, I didn't start a new discussion, as I deem this sufficiently discussed [back in early 2021](https://mail.openjdk.org/pipermail/discuss/2021-March/005779.html).

Sebastian Stenzel has updated the pull request incrementally with one additional commit since the last revision:

  applied latest proposal
  
  result of discussion openjdk/jdk#14099

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Changes:
  - all: https://git.openjdk.org/jdk/pull/14099/files
  - new: https://git.openjdk.org/jdk/pull/14099/files/a7f0e92d..eed69a03

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14099&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14099&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/14099.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14099/head:pull/14099

PR: https://git.openjdk.org/jdk/pull/14099