set up ivar_assignment correctly

for statement tests
and write mom tests
also implement to_mom
and fix local (self) bug

test/vool/to_mom/helper.rb

@@ -1 +1,14 @@
 require_relative "../helper"
+
+module MomCompile
+  include CompilerHelper
+
+  def compile_first_method input
+    lst = Vool::VoolCompiler.compile as_main( input )
+    assert_equal Parfait::Class , lst.clazz.class , input
+    method = lst.clazz.get_method(:main)
+    assert method
+    lst.to_mom( nil ).first
+  end
+
+end