Remove `NtPat`.

The one notable test change is `tests/ui/macros/trace_faulty_macros.rs`.
This commit removes the complicated `Interpolated` handling in
`expected_expression_found` that results in a longer error message. But
I think the new, shorter message is actually an improvement.

The original complaint was in #71039, when the error message started
with "error: expected expression, found `1 + 1`". That was confusing
because `1 + 1` is an expression. Other than that, the reporter said
"the whole error message is not too bad if you ignore the first line".

Subsequently, extra complexity and wording was added to the error
message. But I don't think the extra wording actually helps all that
much. In particular, it still says of the `1+1` that "this is expected
to be expression". This repeats the problem from the original complaint!

This commit removes the extra complexity, reverting to a simpler error
message. This is primarily because the traversal is a pain without
`Interpolated` tokens. Nonetheless, I think the error message is
*improved*. It now starts with "expected expression, found `pat`
metavariable", which is much clearer and the real problem. It also
doesn't say anything specific about `1+1`, which is good, because the
`1+1` isn't really relevant to the error -- it's the `$e:pat` that's
important.

4 files changed, 6 insertions, 6 deletions

diff --git a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs
index 30f3781bf77..1a0833ebb2f 100644
--- a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs
+++ b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs
@@ -12,7 +12,7 @@ macro_rules! mac2 {
     ($eval:pat) => {
         let mut $eval = ();
         //~^ ERROR `mut` must be followed by a named binding
-        //~| ERROR expected identifier, found `does_not_exist!()`
+        //~| ERROR expected identifier, found metavariable
     };
 }
 
diff --git a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr
index dda37d83282..59e1b64686b 100644
--- a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr
+++ b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr
@@ -15,11 +15,11 @@ LL -         let mut $eval = ();
 LL +         let $eval = ();
    |
 
-error: expected identifier, found `does_not_exist!()`
+error: expected identifier, found metavariable
   --> $DIR/issue-65122-mac-invoc-in-mut-patterns.rs:13:17
    |
 LL |         let mut $eval = ();
-   |                 ^^^^^ expected identifier
+   |                 ^^^^^ expected identifier, found metavariable
 ...
 LL |     mac2! { does_not_exist!() }
    |     --------------------------- in this macro invocation
diff --git a/tests/ui/parser/mut-patterns.rs b/tests/ui/parser/mut-patterns.rs
index 45968a516e3..ed33968c627 100644
--- a/tests/ui/parser/mut-patterns.rs
+++ b/tests/ui/parser/mut-patterns.rs
@@ -45,7 +45,7 @@ pub fn main() {
     // Make sure we don't accidentally allow `mut $p` where `$p:pat`.
     macro_rules! foo {
         ($p:pat) => {
-            let mut $p = 0; //~ ERROR expected identifier, found `x`
+            let mut $p = 0; //~ ERROR expected identifier, found metavariable
         }
     }
     foo!(x);
diff --git a/tests/ui/parser/mut-patterns.stderr b/tests/ui/parser/mut-patterns.stderr
index 43f6a344bf3..9dda2499f03 100644
--- a/tests/ui/parser/mut-patterns.stderr
+++ b/tests/ui/parser/mut-patterns.stderr
@@ -158,11 +158,11 @@ LL -     let mut W(mut a, W(b, W(ref c, W(d, B { box f }))))
 LL +     let W(mut a, W(mut b, W(ref c, W(mut d, B { box mut f }))))
    |
 
-error: expected identifier, found `x`
+error: expected identifier, found metavariable
   --> $DIR/mut-patterns.rs:48:21
    |
 LL |             let mut $p = 0;
-   |                     ^^ expected identifier
+   |                     ^^ expected identifier, found metavariable
 ...
 LL |     foo!(x);
    |     ------- in this macro invocation