Support Annex B.3.3

[arai-a]

https://tc39.es/ecma262/#sec-block-level-function-declarations-web-legacy-compatibility-semantics

To achieve this:

• when visiting a function inside a block
  • mark the as possibly-annex
• when leaving a scope
  • propagate the list of possibly-annex functions to enclosing scope
    • currently, at this point, the function is converted into an element of LexicalScopeData.base.bindings
    • the list should contain:
      • ScopeIndex for the scope
      • the index of the function in BaseScopeData.bindings
      • FunctionStencilIndex for the function
      • map from SourceAtomSetIndex to function
    • => HashMap<SourceAtomSetIndex, Vec<(ScopeIndex, usize, FunctionStencilIndex)>> ?
• when leaving a scope that can conflict with var
  • if there's any conflicting declarations, remove the function from the list of possibly-annex functions
• when leaving a var scope
  • makr all possibly-annex functions annex
    • this needs modification to elements in LexicalScopeData.base.bindings
    • also, modify FunctionStencil for those functions, to mark annex
    • append the function to GlobalScopeData.functions

At the same time, it would be better to stop using AssociatedDataKey, but use FunctionStencilIndex instead, to identify functions.

[arai-a]

wait, I guess I was using "hoisted" in wrong meaning here