Get rid of clean::{Method, TyMethod}

[jyn514]

They're redundant and almost the same as clean::Function.

I needed this for #78082, although I forget why.

r? @GuillaumeGomez

[jyn514]

Here's why I needed it for doctree:

error[E0308]: mismatched types
    --> src/librustdoc/html/render/mod.rs:1771:92
     |
1769 |     match item.kind {
     |           --------- this expression has type `types::ItemKind`
1770 |         clean::ModuleItem(ref m) => item_module(buf, cx, item, &m.items),
1771 |         clean::FunctionItem(ref f) | clean::ForeignFunctionItem(ref f) | clean::MethodItem(ref f) | clean::TyMethodItem(ref f) => {
     |                             ----- first introduced with type `&types::Function` here       ^^^^^ expected struct `types::Function`, found struct `types::Method`
     |
     = note: in the same arm, a binding must have the same type in all alternatives

Don't ask me why I need to match both of these in the same pattern, without this #78082 ICEs. UPDATE: It turns out this is because doctree was throwing away item names?

rust/src/librustdoc/formats/renderer.rs

Lines 99 to 100 in 9b2b02a

	} else if item.name.is_some() {
	cx.item(item, &cache)?;

[GuillaumeGomez]

Nice, thanks!

@bors: r+

[bors]

📌 Commit 2a991e1 has been approved by GuillaumeGomez