Teach parser to understand fake anonymous enum syntax

Parse `-> Ty | OtherTy`.
Parse type ascription in top level patterns.

3 files changed, 154 insertions, 18 deletions

diff --git a/tests/ui/parser/anon-enums.rs b/tests/ui/parser/anon-enums.rs
new file mode 100644
index 00000000000..a8b5e8359d9
--- /dev/null
+++ b/tests/ui/parser/anon-enums.rs
@@ -0,0 +1,19 @@
+fn foo(x: bool | i32) -> i32 | f64 {
+//~^ ERROR anonymous enums are not supported
+//~| ERROR anonymous enums are not supported
+    match x {
+        x: i32 => x, //~ ERROR expected
+        //~^ ERROR failed to resolve
+        true => 42.,
+        false => 0.333,
+    }
+}
+
+fn main() {
+    match foo(true) {
+        42: i32 => (), //~ ERROR expected
+        _: f64 => (), //~ ERROR expected
+        x: i32 => (), //~ ERROR expected
+        //~^ ERROR failed to resolve
+    }
+}
diff --git a/tests/ui/parser/anon-enums.stderr b/tests/ui/parser/anon-enums.stderr
new file mode 100644
index 00000000000..4febf2df0dc
--- /dev/null
+++ b/tests/ui/parser/anon-enums.stderr
@@ -0,0 +1,81 @@
+error: anonymous enums are not supported
+  --> $DIR/anon-enums.rs:1:16
+   |
+LL | fn foo(x: bool | i32) -> i32 | f64 {
+   |           ---- ^ ---
+   |
+   = help: create a named `enum` and use it here instead:
+           enum Name {
+               Variant1(bool),
+               Variant2(i32),
+           }
+
+error: anonymous enums are not supported
+  --> $DIR/anon-enums.rs:1:30
+   |
+LL | fn foo(x: bool | i32) -> i32 | f64 {
+   |                          --- ^ ---
+   |
+   = help: create a named `enum` and use it here instead:
+           enum Name {
+               Variant1(i32),
+               Variant2(f64),
+           }
+
+error: expected one of `@` or `|`, found `:`
+  --> $DIR/anon-enums.rs:5:10
+   |
+LL |         x: i32 => x,
+   |          ^ --- specifying the type of a pattern isn't supported
+   |          |
+   |          expected one of `@` or `|`
+   |
+help: maybe write a path separator here
+   |
+LL |         x::i32 => x,
+   |          ~~
+
+error: expected one of `...`, `..=`, `..`, or `|`, found `:`
+  --> $DIR/anon-enums.rs:14:11
+   |
+LL |         42: i32 => (),
+   |           ^ --- specifying the type of a pattern isn't supported
+   |           |
+   |           expected one of `...`, `..=`, `..`, or `|`
+
+error: expected `|`, found `:`
+  --> $DIR/anon-enums.rs:15:10
+   |
+LL |         _: f64 => (),
+   |          ^ --- specifying the type of a pattern isn't supported
+   |          |
+   |          expected `|`
+
+error: expected one of `@` or `|`, found `:`
+  --> $DIR/anon-enums.rs:16:10
+   |
+LL |         x: i32 => (),
+   |          ^ --- specifying the type of a pattern isn't supported
+   |          |
+   |          expected one of `@` or `|`
+   |
+help: maybe write a path separator here
+   |
+LL |         x::i32 => (),
+   |          ~~
+
+error[E0433]: failed to resolve: use of undeclared crate or module `x`
+  --> $DIR/anon-enums.rs:5:9
+   |
+LL |         x: i32 => x,
+   |         ^ use of undeclared crate or module `x`
+
+error[E0433]: failed to resolve: use of undeclared crate or module `x`
+  --> $DIR/anon-enums.rs:16:9
+   |
+LL |         x: i32 => (),
+   |         ^ use of undeclared crate or module `x`
+
+error: aborting due to 8 previous errors
+
+For more information about this error, try `rustc --explain E0433`.
diff --git a/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr b/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr
index 2050a16beb3..ed05bfe8b0a 100644
--- a/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr
+++ b/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr
@@ -2,82 +2,118 @@ error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:17:12
    |
 LL |         Foo:Bar => {}
-   |            ^
+   |            ^--- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         Foo::Bar => {}
+   |            ~~
 
 error: expected one of `!`, `(`, `...`, `..=`, `..`, `::`, `{`, or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:23:17
    |
 LL |         qux::Foo:Bar => {}
-   |                 ^
+   |                 ^--- specifying the type of a pattern isn't supported
    |                 |
    |                 expected one of 8 possible tokens
-   |                 help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         qux::Foo::Bar => {}
+   |                 ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:29:12
    |
 LL |         qux:Foo::Baz => {}
-   |            ^
+   |            ^-------- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         qux::Foo::Baz => {}
+   |            ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:35:12
    |
 LL |         qux: Foo::Baz if true => {}
-   |            ^
+   |            ^ -------- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         qux::Foo::Baz if true => {}
+   |            ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:40:15
    |
 LL |     if let Foo:Bar = f() {
-   |               ^
+   |               ^--- specifying the type of a pattern isn't supported
    |               |
    |               expected one of `@` or `|`
-   |               help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |     if let Foo::Bar = f() {
+   |               ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:48:16
    |
 LL |         ref qux: Foo::Baz => {}
-   |                ^
+   |                ^ -------- specifying the type of a pattern isn't supported
    |                |
    |                expected one of `@` or `|`
-   |                help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         ref qux::Foo::Baz => {}
+   |                ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:57:16
    |
 LL |         mut qux: Foo::Baz => {}
-   |                ^
+   |                ^ -------- specifying the type of a pattern isn't supported
    |                |
    |                expected one of `@` or `|`
-   |                help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         mut qux::Foo::Baz => {}
+   |                ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:68:12
    |
 LL |         Foo:Bar::Baz => {}
-   |            ^
+   |            ^-------- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         Foo::Bar::Baz => {}
+   |            ~~
 
 error: expected one of `@` or `|`, found `:`
   --> $DIR/issue-87086-colon-path-sep.rs:75:12
    |
 LL |         Foo:Bar => {}
-   |            ^
+   |            ^--- specifying the type of a pattern isn't supported
    |            |
    |            expected one of `@` or `|`
-   |            help: maybe write a path separator here: `::`
+   |
+help: maybe write a path separator here
+   |
+LL |         Foo::Bar => {}
+   |            ~~
 
 error[E0433]: failed to resolve: `Bar` is a variant, not a module
   --> $DIR/issue-87086-colon-path-sep.rs:68:13