doesn't come first

ecj incorrectly assigns null module name for all input files that
are listed before module-info.java. The fix is to perform
a separate pass searching for module-info.java and assigning
module names.

This improves javac comatibility and allows ecj to be used
with maven-compiler-plugin on modular projects.

Signed-off-by: Nikita Nemkin <nikita@nemkin.ru>
Change-Id: Idd3fc6b67aa03d0e2184e4265dfe25ff57f225f5
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.core/+/188766
Tested-by: JDT Bot <jdt-bot@eclipse.org>
Reviewed-by: Jay Arthanareeswaran <jarthana@in.ibm.com>