Remove old quasi quoting APIs

[Manishearth]

We still have the quote_foo! macros. They aren't used anywhere within rustc, and they are used by cargo and clippy for testing syntax extension related things.

We can update cargo and clippy to use other APIs (and eventually move them to TokenStream).

rust-lang/cargo#4838 is the cargo PR; will make a clippy one shortly.

[Manishearth]

Cargo landed. Blocked on rust-lang/rust-clippy#2283

[Mark-Simulacrum]

Clippy is also now fixed. I believe the main decision to be made here is whether to remove the old quote_ tests unilaterally or attempt to likewise convert them to either proc_macro and/or manual expansions of the quote_ macros. I lean towards simply removing them.

If we're to just remove them, then this should be a fairly easy PR to make.

[Manishearth]

Okay, so the code that needs to be changed is at

rust/src/libsyntax_ext/lib.rs

Lines 85 to 101 in e063518

	if enable_quotes {
	use syntax::ext::quote::*;
	register! {
	quote_tokens: expand_quote_tokens,
	quote_expr: expand_quote_expr,
	quote_ty: expand_quote_ty,
	quote_item: expand_quote_item,
	quote_pat: expand_quote_pat,
	quote_arm: expand_quote_arm,
	quote_stmt: expand_quote_stmt,
	quote_attr: expand_quote_attr,
	quote_arg: expand_quote_arg,
	quote_block: expand_quote_block,
	quote_meta_item: expand_quote_meta_item,
	quote_path: expand_quote_path,
	}
	}

. We need to remove that, and any other peripheral stuff related to it like the enable_quotes stuff.

Then delete the tests for it. There shouldn't be any uses left.

[est31]

Seems that cargo still uses quote inside a #![feature] attr. Made a pr to remove it rust-lang/cargo#5647