Treat ordinary and generator function expressions inside class static
blocks as boundaries for await binding names, while still rejecting
await as an arrow parameter in the static block itself.
Parse field initializers without inheriting an enclosing async
function's await-expression context, so script field initializers can
resolve await as an identifier while computed field names still use the
enclosing expression context.
Cover static block function expressions, class field initializers, and
the AST shape for an await arrow inside a nested function.
