Numbers and string literals not allowed as property names

The spec says string literals and numeric literals should be allowed as property names in class definitions, but the compiler won't allow it.
https://tc39.github.io/ecma262/#prod-LiteralPropertyName

https://closure-compiler-debugger.appspot.com/#input0%3Dclass%2520Foo%2520%257B%250A%2520%2520'hello'()%2520%257B%2520return%2520'hello'%253B%2520%257D%250A%257D%26input1%26conformanceConfig%26externs%26refasterjs-template%26includeDefaultExterns%3D1%26CHECK_SYMBOLS%3D1%26CHECK_TYPES%3D1%26CLOSURE_PASS%3D1%26LANG_IN_IS_ES6%3D1%26MISSING_PROPERTIES%3D1%26PRESERVE_TYPE_ANNOTATIONS%3D1%26PRETTY_PRINT%3D1%26TRANSPILE%3D1