Provide better error message when using :: in java_import (fixes #2074)
Remove roque printStackTrace.
Update to invokebinder 1.4.
Switch travis to spec:ruby:fast.

Unfortunately the many specs that re-spawn JRuby are now causing
the build to time out. We have work to do on speeding up boot time
for 9k, but right now we need to get green spec runs on travis.

We can also set up longer test runs on our Jenkins instance. That
may be more appropriate for the long-running suites.
Handle ELOOP in File.open call chain.
Le sigh...remove rogue printStackTrace.
Remove old AST decorators and related specs.

The AST is no longer considered our lowest executable
representation of code, since it requires additional processing
via the IR subsystem. The deleted specs would also need to keep up
with changes to how AST nodes are converted into IR and how to
launch that IR directly into the interpreter. These features are
also not (as far as we know) in use by anyone other than core
JRuby folks (e.g. the jrubyc top-level logic that will have to
be rewritten anyway). For these reasons, I believe it's best that
we remove the functionality and if anyone really needs it we can
spin off a gem that provides the lost functionality in some form.
[Truffle] Boxing node should be using the DSL.
[Truffle] Remove a couple of unused nodes.
[Truffle] Annotate some nodes that don't result in any machine code, to better inform the inliner.
Fix defined?(::Object) logic in JIT. Partial fix for #2090.

The current IR for this logic uses the runtime helper call
isDefinedConstantOrMethod, which can trigger exceptions on its own
(if e.g. the method lookup triggers an error?). Because of that
handler, this bug in the JIT was caught and swallowed, resulting
in the defined? returning nil. That is not correct behavior; only
the exceptions we would expect to be raised by these lookups
should be caught.

In addition, I don't believe the :: form can be used to call
methods (::foo doesn't parse), so the use of exception handling
and isDefinedConstOrMethod may be inappropriate here.
Mark runtime_helper helper methods with JIT annotation.
[Truffle] +@ should be defined on Numeric.
[Truffle] Move #nonzero? to Numeric.
[Truffle] Move #times to Numeric.
[Truffle] Add missing "take nodes intro account" lines.
[Truffle] Move Fixnum methods belonging to Integer and Numeric.
[Truffle] Move Class#=== to Module and simplify assignableTo.
Expect j2ee tests to fail, awaiting #2091.
Revert to uncached super logic to fix #2092.

The cached versions of resolved super did not do appropriate arg
splatting as the old versions did. This will need to be remedied.

Also in this commit:

* Pulled out a generic path for all super compiles
* Added Null operand for a simple JVM null value