Reject integer suffix when tuple indexing

src/libsyntax/parse/parser.rs

@@ -3205,14 +3205,7 @@ impl<'a> Parser<'a> {
                         let field = ExprKind::Field(e, Ident::new(name, span));
                         e = self.mk_expr(lo.to(span), field, ThinVec::new());
 
-                        if let Some(suffix) = suffix {
-                            let mut err = self.diagnostic().struct_span_err(
-                                span,
-                                "suffixes on tuple indexes are invalid",
-                            );
-                            err.span_label(span, format!("invalid suffix `{}`", suffix));
-                            err.emit();
-                        }
+                        self.expect_no_suffix(span, "tuple index", suffix);
                     }
                     token::Literal(token::Float(n), _suf) => {
                       self.bump();

src/test/ui/parser/issue-59418.rs

@@ -3,11 +3,10 @@ struct X(i32,i32,i32);
 fn main() {
     let a = X(1, 2, 3);
     let b = a.1suffix;
-    //~^ ERROR suffixes on tuple indexes are invalid
+    //~^ ERROR tuple index with a suffix is invalid
     println!("{}", b);
     let c = (1, 2, 3);
     let d = c.1suffix;
-    //~^ ERROR suffixes on tuple indexes are invalid
+    //~^ ERROR tuple index with a suffix is invalid
     println!("{}", d);
 }
-

src/test/ui/parser/issue-59418.stderr

@@ -1,14 +1,14 @@
-error: suffixes on tuple indexes are invalid
+error: tuple index with a suffix is invalid
   --> $DIR/issue-59418.rs:5:15
    |
 LL |     let b = a.1suffix;
-   |               ^^^^^^^ invalid suffix `suffix`
+   |               ^^^^^^^ tuple index with a suffix is invalid
 
-error: suffixes on tuple indexes are invalid
+error: tuple index with a suffix is invalid
   --> $DIR/issue-59418.rs:9:15
    |
 LL |     let d = c.1suffix;
-   |               ^^^^^^^ invalid suffix `suffix`
+   |               ^^^^^^^ tuple index with a suffix is invalid
 
 error: aborting due to 2 previous errors