Can't parse switch statements inside switch statements

[rewong03]

dump_to_ast.py can parse top level switch statements but it fails if switch statements are nested inside other switch statements. In general switch statements are a pain to parse, because single-token keywords like "case", "default", "break", etc. aren't recognized as root tokens, so you manually have to traverse through the tokens to identify them. Check out this test for an example of a nested switch which isn't properly parsed