Removed Precision specs.
Removed ruby_version_is from ObjectSpace specs.
Removed ruby_version_is from Object specs.
Removed ruby_version_is from Numeric specs.
Removed ruby_version_is from NilClass specs.
Removed ruby_version_is from Mutex specs.
Removed ruby_version_is from Module specs.
Removed ruby_version_is from Method specs.
Removed ruby_version_is from Math specs.
Removed ruby_version_is from MatchData specs.
Removed ruby_version_is from specs.
Updated specs for method_missing.
Removed Kernel#caller specs.

Every implementation uses significantly different methods to implement calling
methods. In MRI, numerous actual frames are invisible because they are in C,
while in Rubinius, these frames are in Ruby and are visible.

It's not realistic or useful to attempt to specify the results of caller.
Further, it's a hack in the first place and a proper object-oriented API for
querying the stack should be created.