Reviewed-by: lagergren, sundar

8012522: Clean up lexical contexts - split out stack based functionality in CodeGenerator and generify NodeVisitors based on their LexicalContext type to avoid casts
Reviewed-by: attila, jlaskey

Reviewed-by: jlaskey, lagergren

Reviewed-by: attila, jlaskey

Reviewed-by: lagergren, sundar