syntax: Rewrite parsing of patterns

src/test/compile-fail/issue-22426-1.rs

@@ -11,7 +11,7 @@
 fn main() {
   match 42 {
     x < 7 => (),
-   //~^ error: unexpected token: `<`
+   //~^ error: expected one of `=>`, `@`, `if`, or `|`, found `<`
     _ => ()
   }
 }

src/test/compile-fail/issue-22426-2.rs

@@ -9,4 +9,4 @@
 // except according to those terms.
 
 fn a(B<) {}
-   //~^ error: unexpected token: `<`
+   //~^ error: expected one of `:` or `@`, found `<`

src/test/compile-fail/issue-22426-3.rs

@@ -14,7 +14,7 @@ impl<T> Foo<T> {
     fn foo(&self) {
         match *self {
             Foo<T>(x, y) => {
-            //~^ error: unexpected token: `<`
+            //~^ error: expected one of `=>`, `@`, `if`, or `|`, found `<`
               println!("Goodbye, World!")
             }
         }

src/test/parse-fail/issue-22647.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 fn main() {
-    let caller<F> = |f: F|  //~ ERROR unexpected token: `<`
+    let caller<F> = |f: F|  //~ ERROR expected one of `:`, `;`, `=`, or `@`, found `<`
     where F: Fn() -> i32
     {
         let x = f();

src/test/parse-fail/issue-22712.rs

@@ -13,7 +13,7 @@ struct Foo<B> {
 }
 
 fn bar() {
-    let Foo<Vec<u8>>  //~ ERROR unexpected token: `<`
+    let Foo<Vec<u8>>  //~ ERROR expected one of `:`, `;`, `=`, or `@`, found `<`
 }
 
 fn main() {}

src/test/parse-fail/match-vec-invalid.rs

@@ -11,7 +11,7 @@
 fn main() {
     let a = Vec::new();
     match a {
-        [1, tail.., tail..] => {}, //~ ERROR: expected one of `!`, `,`, or `@`, found `..`
+        [1, tail.., tail..] => {}, //~ ERROR: expected one of `,` or `@`, found `..`
         _ => ()
     }
 }

src/test/parse-fail/omitted-arg-in-item-fn.rs

@@ -8,5 +8,5 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-fn foo(x) { //~ ERROR expected one of `!`, `:`, or `@`, found `)`
+fn foo(x) { //~ ERROR expected one of `:` or `@`, found `)`
 }

src/test/parse-fail/removed-syntax-larrow-init.rs

@@ -11,5 +11,5 @@
 fn removed_moves() {
     let mut x = 0;
     let y <- x;
-    //~^ ERROR expected one of `!`, `:`, `;`, `=`, or `@`, found `<-`
+    //~^ ERROR expected one of `:`, `;`, `=`, or `@`, found `<-`
 }

src/test/parse-fail/struct-literal-in-match-discriminant.rs

@@ -14,7 +14,7 @@ struct Foo {
 
 fn main() {
     match Foo {
-        x: 3    //~ ERROR expected one of `!`, `=>`, `@`, `if`, or `|`, found `:`
+        x: 3    //~ ERROR expected one of `=>`, `@`, `if`, or `|`, found `:`
     } {
         Foo {
             x: x