SI-3936 - add test case to show that SI-3936 is already fixed

These are exactly the examples given by Lukas Rytz in SI-3936.
They fail with 2.10.1 and compile with 2.10.2 as well as current master.
SI-7600 [Avian] Skip tests r/stream_length and r/t4294

The issue is that Avian's GC is currently not precise enough to
determine the exact lifetime of each local/stack reference, and
therefore considers the this reference to be reachable in situations
where it could have been collected.

This can cause issues (as seen in run/stream_length and run/t4294:
`java.lang.OutOfMemoryError`) if code relies on the garbage collection
of these values to keep memory consumption constant.

This commit simply skips these two tests on Avian until the GC
implementation is fixed.
Get rid of raw types which cause unnecessary warnings
Remove dependency on combinators from CommandLinerParser.

tools.cmd.CommandLineParser uses a small hand-rolled parser

TODO: replace partest's usage of scala.tools.nsc.util.CommandLine
by scala.tools.cmd.CommandLine
Merge pull request #2669 from adriaanm/modularize-parsing

Modularize parsing
Merge pull request #2677 from jannic/SI-3936

SI-3936 - add test case to show that SI-3936 is already fixed
Merge pull request #2678 from soc/SI-7600

SI-7600 [Avian] Skip tests r/stream_length and r/t4294
Merge pull request #2679 from soc/topic/java-rawtype-cleanup

Get rid of raw types which cause unnecessary warnings