Rollup merge of #145378 - xizheyin:144968, r=davidtwco

Add `FnContext` in parser for diagnostic

Fixes rust-lang/rust#144968

Inspired by https://github.com/rust-lang/rust/issues/144968#issuecomment-3156094581, I implemented `FnContext` to indicate whether a function should have a self parameter, for example, whether the function is a trait method, whether it is in an impl block. And I removed the outdated note.

I made two commits to show the difference.

cc ``@estebank`` ``@djc``

r? compiler

1 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs
index 7aacb674253..b4943ff7de6 100644
--- a/compiler/rustc_parse/src/parser/stmt.rs
+++ b/compiler/rustc_parse/src/parser/stmt.rs
@@ -19,8 +19,8 @@ use super::diagnostics::AttemptLocalParseRecovery;
 use super::pat::{PatternLocation, RecoverComma};
 use super::path::PathStyle;
 use super::{
-    AttrWrapper, BlockMode, FnParseMode, ForceCollect, Parser, Restrictions, SemiColonMode,
-    Trailing, UsePreAttrPos,
+    AttrWrapper, BlockMode, FnContext, FnParseMode, ForceCollect, Parser, Restrictions,
+    SemiColonMode, Trailing, UsePreAttrPos,
 };
 use crate::errors::{self, MalformedLoopLabel};
 use crate::exp;
@@ -153,7 +153,7 @@ impl<'a> Parser<'a> {
             attrs.clone(), // FIXME: unwanted clone of attrs
             false,
             true,
-            FnParseMode { req_name: |_| true, req_body: true },
+            FnParseMode { req_name: |_| true, context: FnContext::Free, req_body: true },
             force_collect,
         )? {
             self.mk_stmt(lo.to(item.span), StmtKind::Item(Box::new(item)))