ruby: Convert most Ruby objects to M5 SimObjects.

The necessary companion conversion of Ruby objects generated by SLICC
are converted to M5 SimObjects in the following patch, so this patch
alone does not compile.
Conversion of Garnet network models is also handled in a separate
patch; that code is temporarily disabled from compiling to allow
testing of interim code.

src/mem/ruby/system/SConscript

@@ -33,6 +33,12 @@ Import('*')
 if not env['RUBY']:
     Return()
 
+SimObject('Cache.py')
+SimObject('Sequencer.py')
+SimObject('DirectoryMemory.py')
+SimObject('MemoryControl.py')
+SimObject('RubySystem.py')
+
 Source('DMASequencer.cc')
 Source('DirectoryMemory.cc')
 Source('CacheMemory.cc')