Give `DiagnosticBuilder` a default type.

`IntoDiagnostic` defaults to `ErrorGuaranteed`, because errors are the
most common diagnostic level. It makes sense to do likewise for the
closely-related (and much more widely used) `DiagnosticBuilder` type,
letting us write `DiagnosticBuilder<'a, ErrorGuaranteed>` as just
`DiagnosticBuilder<'a>`. This cuts over 200 lines of code due to many
multi-line things becoming single line things.

1 files changed, 2 insertions, 3 deletions

diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index e653d4064c8..a6783eaf8d4 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -26,8 +26,7 @@ use rustc_ast::{ClosureBinder, MetaItemLit, StmtKind};
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::{
-    AddToDiagnostic, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, PResult,
-    StashKey,
+    AddToDiagnostic, Applicability, Diagnostic, DiagnosticBuilder, PResult, StashKey,
 };
 use rustc_macros::Subdiagnostic;
 use rustc_session::errors::{report_lit_error, ExprParenthesesNeeded};
@@ -1691,7 +1690,7 @@ impl<'a> Parser<'a> {
         &self,
         lifetime: Ident,
         mk_lit_char: impl FnOnce(Symbol, Span) -> L,
-        err: impl FnOnce(&Self) -> DiagnosticBuilder<'a, ErrorGuaranteed>,
+        err: impl FnOnce(&Self) -> DiagnosticBuilder<'a>,
     ) -> L {
         if let Some(mut diag) = self.dcx().steal_diagnostic(lifetime.span, StashKey::LifetimeIsChar)
         {