Rollup merge of rust-lang#119169 - fmease:pretty-yeet-syntactic-cruft, r=compiler-errors

Rid the AST & HIR pretty printer of cruft Found while working on rust-lang#119163. For `trait Trait: ?Sized {}` (semantically malformed), we currently output `trait Trait for ? Sized {}` (sic!) / `trait Trait for ? Sized { }` (sic!) if `-Zunpretty=expanded` / `-Zunpretty=hir` is passed. `trait Tr for Sized? {}` (rust-lang#15521) and later also `trait Tr for ?Sized {}` (I guess, rust-lang#20194) is former Rust syntax. Hence I'm removing these outdated branches. ~~This will conflict with rust-lang#119163, therefore marking this PR as blocked.~~ Rebased

Author: matthiaskrgr

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -5,7 +5,6 @@ use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
 use ast::StaticItem;
 use itertools::{Itertools, Position};
 use rustc_ast as ast;
-use rustc_ast::GenericBound;
 use rustc_ast::ModKind;
 use rustc_span::symbol::Ident;
 
@@ -338,21 +337,9 @@ impl<'a> State<'a> {
  self.word_nbsp("trait");
  self.print_ident(item.ident);
  self.print_generic_params(&generics.params);
- let mut real_bounds = Vec::with_capacity(bounds.len());
- for bound in bounds.iter() {
- if let GenericBound::Trait(ptr, modifiers) = bound
- && let ast::BoundPolarity::Maybe(_) = modifiers.polarity
- {
- self.space();
- self.word_space("for ?");
- self.print_trait_ref(&ptr.trait_ref);
- } else {
- real_bounds.push(bound.clone());
- }
- }
- if !real_bounds.is_empty() {
+ if !bounds.is_empty() {
  self.word_nbsp(":");
- self.print_type_bounds(&real_bounds);
+ self.print_type_bounds(bounds);
  }
  self.print_where_clause(&generics.where_clause);
  self.word(" ");

compiler/rustc_hir_pretty/src/lib.rs

@@ -553,17 +553,7 @@ impl<'a> State<'a> {
  }
  hir::ItemKind::OpaqueTy(opaque_ty) => {
  self.print_item_type(item, opaque_ty.generics, |state| {
- let mut real_bounds = Vec::with_capacity(opaque_ty.bounds.len());
- for b in opaque_ty.bounds {
- if let GenericBound::Trait(ptr, hir::TraitBoundModifier::Maybe) = b {
- state.space();
- state.word_space("for ?");
- state.print_trait_ref(&ptr.trait_ref);
- } else {
- real_bounds.push(b);
- }
- }
- state.print_bounds("= impl", real_bounds);
+ state.print_bounds("= impl", opaque_ty.bounds)
  });
  }
  hir::ItemKind::Enum(ref enum_definition, params) => {
@@ -625,17 +615,7 @@ impl<'a> State<'a> {
  self.word_nbsp("trait");
  self.print_ident(item.ident);
  self.print_generic_params(generics.params);
- let mut real_bounds = Vec::with_capacity(bounds.len());
- for b in bounds {
- if let GenericBound::Trait(ptr, hir::TraitBoundModifier::Maybe) = b {
- self.space();
- self.word_space("for ?");
- self.print_trait_ref(&ptr.trait_ref);
- } else {
- real_bounds.push(b);
- }
- }
- self.print_bounds(":", real_bounds);
+ self.print_bounds(":", bounds);
  self.print_where_clause(generics);
  self.word(" ");
  self.bopen();