Java launcher with `--module=name[/entry-point]` fails on Windows

[Christian Stein]

Hi,

relying on the "Note: To specify an argument for a long option,
you can use either --name=value or --name value." from [0] and
assuming that `--module` is a long option (with `-m` being its
short counterpart) I think I found an error in `java.exe`.

The brief history of the search is recorded at JBS [1], and
yesterday, I managed to create a minimal, complete and
verifiable example at [2] -- which contains a README.md
file with more details. Here's a gist:

Calling `java --module-path=lib --module=m/Main --help ...`
sometimes fails to launch the JVM. The failure, if it occurs,
expresses mostly via a silent exit of the `java.exe` program
leaving a negative value in the "DOS shell" `ERRORLEVEL`
environment variable. Seldom, a fatal error log is written
to the current working directory.

The underlying reason seems to be an error in the
calculation of the application argument count and index.
The later reads: AppArgIndex: -1 points to (null)

Work-around: omit the `=` (equals sign) after `--module`
and the entry-point, here `m/Main`. This command line
always gets the JVM up and running.

Cheers,
Christain

[0] https://docs.oracle.com/en/java/javase/11/tools/java.html
[1] https://bugs.openjdk.java.net/browse/JDK-8234076
[2] https://github.com/sormuras/JDK-8234076