~ fixes after review: reuse InTextDirectivesUtils
~ fixes after review: replace directive for objectClone
~ fixes after review: TestGenerator: remove pattern
add two more tests for bridge methods (fake override)
JS backend: improve test twoParentsWithDifferrentMethodsTwoBridges
regenerate tests
JS backend: add Namer.THIS_NAME_REF constant
extract getTraitMethods from ImplementationBodyGen to CodegenUtil
JS backend: add generateTraitMethods into ClassTranslator
JS backend: extract generateDelegateCall from DelegationTranslator into utils
JS backend: use utils.generateDelegateCall for bridge methods in ClassTranslator