RFR: 8163229: test test/tools/javac/CaptureInSubtype.java has a main method that is never executed Export [v4]

[Archie L. Cobbs]

> This PR deals with some housekeeping relating to compiler unit tests.
> 
> JDK-8163229 points out that there are several tests that have a `public static void main(String[])` method, but because the test expects to fail during compilation, the test is never actually run, and so these `main` methods are just clutter that can be removed.
> 
> However, there are also some tests where the test is never run, but the `main()` method generates one or more of the expected compilation errors. Obviously we need to keep those, but they don't need to be declared as `public static void main(String[])` which is misleading. So instead we rename these methods to `meth()`, and also we remove the `String[]` parameter when it's not needed by the test.

Archie L. Cobbs has updated the pull request incrementally with one additional commit since the last revision:

  Remove two more unnecessary main() methods.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/10992/files
  - new: https://git.openjdk.org/jdk/pull/10992/files/6987fbda..501289c4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10992&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10992&range=02-03

  Stats: 4 lines in 2 files changed: 0 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/10992.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10992/head:pull/10992

PR: https://git.openjdk.org/jdk/pull/10992