Add specs for Enumerable#zip
Fix Enumerable#zip for shorter lists on X19
Add a spec for Module#<
Add a spec for Module#>
Fix Module#< when other is an own child
Simplify Module#<=
Simplify Module#>=
Simplify Module#<=>
Bump default Fiber stack size to 512k

Looks like this can be an issue for example when compiling Ruby code
from a fiber. Whether that's a good idea or not is a different
discussion, but we want to be a bit on the safe side here with this
size.

Fixes #2308
Add spec for IO.readlines using the default external encoding
Use the correct encoding in IO.readlines, IO#gets, etc

Fixes #2306
Remove hardcoded dependency on C preprocessor

Invoke the preprocessor through the specified compiler. This make sure
that we also run this with the same compiler as we're building with.
Update specs for DependencyGrapher
accept a Symbol as the second argument to Signal.trap(…).

On 1.9 mode Signal.trap can take a Symbol as a second argument in place of a
String. For example, you can say:

  Signal.trap :SIGUSR1, :DEFAULT
  Signal.trap :SIGUSR1, :SIG_DFT
  Signal.trap :SIGUSR1, :SIG_IGN
  Signal.trap :SIGUSR1, :IGNORE

I found this while trying to use Foreman on Rubinius. It has code that uses
:DEFAULT in place of "DEFAULT".

Side-note:
MRI 1.9 & 1.8 behavior is to accept any string or symbol as the second argument.
Rubinius(1.8 & 1.9) mode raise when the second argument isn't something it
understands. This is valid on CRuby, but not rubinius:

  Signal.trap :SIGUSR1, "ninja"
add specs.
Merge pull request #2321 from robgleeson/patch/signal-trap

accept a Symbol as the second argument to Signal.trap(…).
Fix indent in generated code
Move CompiledCode specs to correct directory
Generate global symbol names for primitives

Before the primitive hookup logic actually took around 0.2s on my system
of the startup time. This was due to how the algorithm works, basically
resulting in number of primitives squared symbol lookups.

With generating these names like this, we remove the string to symbol
lookup needed, resulting in 0.2s faster startup on my system.
Update specs to make Rubinius compliant with masgn_spec return value

Previously, Rubinius was explicitly non-compliant with regards to the
return values of mass-assignment expressions, always returning true
instead.