cmd/compile/internal/types2: review of examples test

The only changes between (equivalent, and reviewed) go/types/examples directory
are in examples/types.go2. The go/types/examples/types.go2 file should be updated
accordingly.

$ f=examples/types.go2; diff $f $HOME/goroot/src/go/types/$f
1d0
< // UNREVIEWED
109c108
< var _ (T /* ERROR cannot use generic type T */ )[ /* ERROR unexpected \[ */ int]
---
> var _ (T /* ERROR cannot use generic type T */ )[ /* ERROR expected ';' */ int]
147a147,154
> // We accept parenthesized embedded struct fields so we can distinguish between
> // a named field with a parenthesized type foo (T) and an embedded parameterized
> // type (foo(T)), similarly to interface embedding.
> // They still need to be valid embedded types after the parentheses are stripped
> // (i.e., in contrast to interfaces, we cannot embed a struct literal). The name
> // of the embedded field is derived as before, after stripping parentheses.
> // (7/14/2020: See comment above. We probably will revert this generalized ability
> // if we go with [] for type parameters.)
149,152c156,158
< 	( /* ERROR cannot parenthesize */ int8)
< 	( /* ERROR cannot parenthesize */ *int16)
< 	*( /* ERROR cannot parenthesize */ int32)
< 	List[int]
---
> 	int8
> 	*int16
> 	*List[int]
155,156c161
< 	* /* ERROR int16 redeclared */ int16
< 	List /* ERROR List redeclared */ [int]
---
> 	* /* ERROR List redeclared */ List[int]
280a286
>

The actual changes are removing the "// UNREVIEWED" markers.

Change-Id: I8a80fa11f3c84f9a403c690b537973a53e1adc2c
Reviewed-on: https://go-review.googlesource.com/c/go/+/304250
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>

src/cmd/compile/internal/types2/examples/functions.go2

@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2019 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

src/cmd/compile/internal/types2/examples/methods.go2

@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2019 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

src/cmd/compile/internal/types2/examples/types.go2

@@ -1,4 +1,3 @@
-// UNREVIEWED
 // Copyright 2019 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.