go/types, types2: qualify named types in error messages with type kind

Change the description of an operand x that has a named type of sorts
by providing a description of the type structure (array, struct, slice,
pointer, etc).

For instance, given a (variable) operand x of a struct type T, the
operand is mentioned as (new):

        x (variable of struct type T)

instead of (old):

        x (variable of type T)

This approach is also used when a basic type is renamed, for instance
as in:

        x (value of uint type big.Word)

which makes it clear that big.Word is a uint.

This change is expected to produce more informative error messages.

Fixes #69955.

Change-Id: I544b0698f753a522c3b6e1800a492a94974fbab7
Reviewed-on: https://go-review.googlesource.com/c/go/+/621458
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/test/fixedbugs/issue48471.go b/test/fixedbugs/issue48471.go
index 75875c4004..a834c80675 100644
--- a/test/fixedbugs/issue48471.go
+++ b/test/fixedbugs/issue48471.go
@@ -51,6 +51,6 @@ func g() {
 	_ = i.(T6)  // ERROR "impossible type assertion: i.\(T6\)\n\tT6 does not implement I \(missing method M\)\n\t\thave m\(int\) string\n\t\twant M\(int\)"
 
 	var t *T4
-	t = i // ERROR "cannot use i \(variable of type I\) as \*T4 value in assignment: need type assertion"
+	t = i // ERROR "cannot use i \(variable of interface type I\) as \*T4 value in assignment: need type assertion"
 	_ = t
 }