generalize get_main and get_init to get_method

to get at those know methods that really
__must__ exists, hence the bang, raise if don't
about to add method missing and raise to the list

test/risc/test_builder.rb

@@ -6,8 +6,8 @@ module Risc
     def setup
       Parfait.boot!(Parfait.default_test_options)
       Risc.boot!
-      init = Parfait.object_space.get_init
-      @builder = Risc::MethodCompiler.new( init ,Mom::Label.new( "source_name", "return_label")).builder(init)
+      label = Mom::Label.new( "source_name", "return_label")
+      @builder = Risc::MethodCompiler.new( FakeCallable.new ,label).builder("source")
       @label = Risc.label("source","name")
       @start = @builder.compiler.current
     end

test/risc/test_builder2.rb

@@ -6,9 +6,9 @@ module Risc
     def setup
       Parfait.boot!(Parfait.default_test_options)
       Risc.boot!
-      @init = Parfait.object_space.get_init
-      @compiler = Risc::MethodCompiler.new( @init, Mom::Label.new( "source_name", "return_label") )
-      @builder  = @compiler.builder(@init)
+      method = FakeCallable.new
+      @compiler = Risc::MethodCompiler.new( method, Mom::Label.new( "source_name", "return_label") )
+      @builder  = @compiler.builder(method)
     end
     def test_list
       assert_equal :List , @builder.infer_type(:list).class_name

test/risc/test_linker.rb

@@ -30,11 +30,11 @@ module Risc
       assert_equal Position ,  Position.get(@linker.cpu_init.first).class
     end
     def test_first_binary_jump
-      bin = Parfait.object_space.get_init.binary
+      bin = Parfait.object_space.get_method!(:Object,:__init__).binary
       assert_equal 116 , bin.total_byte_length
     end
     def test_second_binary_first
-      bin = Parfait.object_space.get_init.binary
+      bin = Parfait.object_space.get_method!(:Object,:__init__).binary
       assert 0 != bin.get_word(0) , "index 0 is 0 #{bin.inspect}"
     end
     def test_positions_set