Due to JEP 260 (Encapsulate Most Internal APIs), aspect weaving on
Java 16 now requires '--add-opens java.base/java.lang=ALL-UNNAMED' on
the command line. Otherwise there will be illegal access exceptions for
some internal API calls AspectJ needs, most prominently when trying to
define classes in other packages or modules.

This had to be done on several levels:

  - Maven Surefire: running tests in a JVM directly forked by Surefire.
    In order to make this backwards compatible, I added two profiles
    with JDK-level-dependent auto-activation, one 8-15 and one 16+. In
    the latter a property containing the JVM parameter is defined, in
    the former it is empty, i.e. the JVM is started without the
    parameter. In Java 8 the parameter did not even exist, in Java 9+ we
    could use it, but we need to test how users use AspectJ.

  - RunSpec: Whenever an XML test is declared to use '<run>', we need to
    determine the current JVM version and again dynamically add the
    parameter when forking the target JVM.

  - AntSpec: Whenever an XML test is declared to use '<ant>', we need to
    determine the current JVM version dynamically add two properties
    usable from within Ant scripts: 'aj.addOpensKey' and
    'aj.addOpensValue'. Unfortunately, Ant needs to use two '<argLine>'
    parameters, because the two parts of the option are separated by a
    space character.

  - Ant scripts: When triggered by an AntSpec, each Ant target using LTW
    needs to manually set
      <jvmarg value="${aj.addOpensKey}"/>
      <jvmarg value="${aj.addOpensValue}"/>
    for each '<java>' task. It was quite tedious to find all(?) of them.

TODO: In the AspectJ 1.9.7 release notes we need to document that this
parameter is now needed for LTW.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

Reports on declarations of Collection variables made by using the collection class as the type, rather than an appropriate interface.

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

Reports Collection.addAll() and Map.putAll() calls after instantiation of a collection using a constructor call without arguments. Such constructs can be replaced with a single call to a parametrized constructor which simplifies code. Also for some collections the replacement might be more performant.

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

Reports "unboxing", e.g. explicit unwrapping of wrapped primitive values. Unboxing is unnecessary under Java 5 and newer, and can be safely removed.

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

Reports any String.indexOf() expressions which can be replaced with a call to the String.contains() method available in Java 5 and newer.

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

Reports for loops which iterate over collections or arrays, and can be replaced with an enhanced for loop (i.e. the foreach iteration syntax).

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

incremental tests need to ensure that AjState runs in incremental mode!

 	wrong line for method execution join point

removed unused imports, local variables, and private methods
(still there, just commented out).