review comments

src/libsyntax/parse/parser.rs

@@ -3208,7 +3208,7 @@ impl<'a> Parser<'a> {
                         if let Some(suffix) = suffix {
                             let mut err = self.diagnostic().struct_span_err(
                                 span,
-                                "tuple index with a suffix is invalid",
+                                "suffixes on tuple indexes are invalid",
                             );
                             err.span_label(span, format!("invalid suffix `{}`", suffix));
                             err.emit();

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

@@ -3,7 +3,11 @@ struct X(i32,i32,i32);
 fn main() {
     let a = X(1, 2, 3);
     let b = a.1suffix;
-    //~^ ERROR tuple index with a suffix is invalid
+    //~^ ERROR suffixes on tuple indexes are invalid
     println!("{}", b);
+    let c = (1, 2, 3);
+    let d = c.1suffix;
+    //~^ ERROR suffixes on tuple indexes are invalid
+    println!("{}", d);
 }
 

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

@@ -1,8 +1,14 @@
-error: tuple index with a suffix is invalid
+error: suffixes on tuple indexes are invalid
   --> $DIR/issue-59418.rs:5:15
    |
 LL |     let b = a.1suffix;
    |               ^^^^^^^ invalid suffix `suffix`
 
-error: aborting due to previous error
+error: suffixes on tuple indexes are invalid
+  --> $DIR/issue-59418.rs:9:15
+   |
+LL |     let d = c.1suffix;
+   |               ^^^^^^^ invalid suffix `suffix`
+
+error: aborting due to 2 previous errors