several larger changes came together, bit of cleaning too

- all code must be in functions (which must be in classes).
— changes a fair few tests
— also changes api, as method is not recursive, not passed around
- all state in instance vars in compiler (no accessors)
- class is another such variable, surely more coming
all green again

test/compiler/test_all.rb

@@ -1,4 +1,3 @@
-require_relative "test_basic"
 require_relative "test_methods"
 require_relative "test_hello"
 require_relative "test_compiler"