Make span_suggestions take IntoIterator

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -698,7 +698,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                                     ),
                                     (rv.span.shrink_to_hi(), ")".to_string()),
                                 ],
-                            ].into_iter(),
+                            ],
                             Applicability::MachineApplicable,
                         );
                         self.suggested = true;

compiler/rustc_errors/src/diagnostic.rs

@@ -717,7 +717,7 @@ impl Diagnostic {
         &mut self,
         sp: Span,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestions: impl Iterator<Item = String>,
+        suggestions: impl IntoIterator<Item = String>,
         applicability: Applicability,
     ) -> &mut Self {
         self.span_suggestions_with_style(
@@ -738,7 +738,7 @@ impl Diagnostic {
         applicability: Applicability,
         style: SuggestionStyle,
     ) -> &mut Self {
-        let mut suggestions: Vec<_> = suggestions.collect();
+        let mut suggestions: Vec<_> = suggestions.into_iter().collect();
         suggestions.sort();
 
         debug_assert!(
@@ -765,7 +765,7 @@ impl Diagnostic {
     pub fn multipart_suggestions(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestions: impl Iterator<Item = Vec<(Span, String)>>,
+        suggestions: impl IntoIterator<Item = Vec<(Span, String)>>,
         applicability: Applicability,
     ) -> &mut Self {
         let suggestions: Vec<_> = suggestions.collect();

compiler/rustc_errors/src/diagnostic_builder.rs

@@ -599,13 +599,13 @@ impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
         &mut self,
         sp: Span,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestions: impl Iterator<Item = String>,
+        suggestions: impl IntoIterator<Item = String>,
         applicability: Applicability,
     ) -> &mut Self);
     forward!(pub fn multipart_suggestions(
         &mut self,
         msg: impl Into<SubdiagnosticMessage>,
-        suggestions: impl Iterator<Item = Vec<(Span, String)>>,
+        suggestions: impl IntoIterator<Item = Vec<(Span, String)>>,
         applicability: Applicability,
     ) -> &mut Self);
     forward!(pub fn span_suggestion_short(

compiler/rustc_parse/src/parser/ty.rs

@@ -401,7 +401,7 @@ impl<'a> Parser<'a> {
                 .span_suggestions(
                     span.shrink_to_hi(),
                     "add `mut` or `const` here",
-                    ["mut ".to_string(), "const ".to_string()].into_iter(),
+                    ["mut ".to_string(), "const ".to_string()],
                     Applicability::HasPlaceholders,
                 )
                 .emit();

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1941,7 +1941,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 err.span_suggestions(
                     span,
                     &msg,
-                    suggestable_variants.into_iter(),
+                    suggestable_variants,
                     Applicability::MaybeIncorrect,
                 );
             }
@@ -1995,7 +1995,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 err.span_suggestions(
                     span,
                     msg,
-                    suggestable_variants.into_iter(),
+                    suggestable_variants,
                     Applicability::MaybeIncorrect,
                 );
             }
@@ -2025,7 +2025,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 err.span_suggestions(
                     span,
                     msg,
-                    suggestable_variants_with_placeholders.into_iter(),
+                    suggestable_variants_with_placeholders,
                     Applicability::HasPlaceholders,
                 );
             }

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -1117,7 +1117,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         err.span_suggestions(
                             span.shrink_to_lo(),
                             "consider borrowing here",
-                            ["&".to_string(), "&mut ".to_string()].into_iter(),
+                            ["&".to_string(), "&mut ".to_string()],
                             Applicability::MaybeIncorrect,
                         );
                     } else {