Consider supporting new syntax of --module-source-path

[stephan-herrmann]

JEP 261 defines syntax for --module-source-path which is out of sync with what javac actually supports, see https://docs.oracle.com/en/java/javase/23/docs/specs/man/javac.html#the-module-source-path-option

See in particular this variant:

    --module-source-path module-name=file-path (path-separator file-path)*

Should ecj support the same syntax options?

[stephan-herrmann]

This is not a standard feature in the sense of the JCP, but came in via https://bugs.openjdk.org/browse/JDK-8208609