hard to read the implied double negative
fix for parsing x() as identifier pattern
parser comments
needs_comma was always true
parser comments
rename parse_class_item to parse_struct_decl_field

two problems with the old name: they're not called classes any more, and
the word "item" has a specific connotation in the parser
rename parse_single_class_item as well
remove obsolete semicolon from list of suggestions
rename parse_instance_var to parse_name_and_ty

the name no longer made sense. perhaps this could just be inlined.
parser comments
remove 3-line used-once function
s/parse_purity/parse_unsafety
parser comments
parser comments
removed unneeded argument to parse_record
s/one_tuple/trailing_comma (more accurate name)
parser comments
removed old type dispatch test
deleted two tests intended to test RUST_CC_ZEAL, an apparently defunct flag for the cycle collector
remove (non-parsing) test related to impl d for d feature