cmd/compile: allow importing and exporting of ODYNAMICTYPE

Change-Id: I2fca7a801c85ed93c002c23bfcb0cf9593f1bdf4
Reviewed-on: https://go-review.googlesource.com/c/go/+/356571
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>

2 files changed, 42 insertions, 0 deletions

diff --git a/test/typeparam/issue49027.dir/a.go b/test/typeparam/issue49027.dir/a.go
index d3ec27deab..da88297965 100644
--- a/test/typeparam/issue49027.dir/a.go
+++ b/test/typeparam/issue49027.dir/a.go
@@ -15,7 +15,41 @@ func conv[T any](v interface{}) T {
 func Conv2(v interface{}) (string, bool) {
 	return conv2[string](v)
 }
+
 func conv2[T any](v interface{}) (T, bool) {
 	x, ok := v.(T)
 	return x, ok
 }
+
+func Conv3(v interface{}) string {
+	return conv3[string](v)
+}
+
+func conv3[T any](v interface{}) T {
+	switch v := v.(type) {
+	case T:
+		return v
+	default:
+		var z T
+		return z
+	}
+}
+
+type Mystring string
+
+func (Mystring) Foo() {
+}
+
+func Conv4(v interface{Foo()}) Mystring {
+	return conv4[Mystring](v)
+}
+
+func conv4[T interface{Foo()}](v interface{Foo()}) T {
+	switch v := v.(type) {
+	case T:
+		return v
+	default:
+		var z T
+		return z
+	}
+}
diff --git a/test/typeparam/issue49027.dir/main.go b/test/typeparam/issue49027.dir/main.go
index d0dc33d734..aa20a2fdfb 100644
--- a/test/typeparam/issue49027.dir/main.go
+++ b/test/typeparam/issue49027.dir/main.go
@@ -22,4 +22,12 @@ func main() {
 	if y != s {
 		panic(fmt.Sprintf("got %s wanted %s", y, s))
 	}
+	z := a.Conv3(s)
+	if z != s {
+		panic(fmt.Sprintf("got %s wanted %s", z, s))
+	}
+	w := a.Conv4(a.Mystring(s))
+	if w != a.Mystring(s) {
+		panic(fmt.Sprintf("got %s wanted %s", w, s))
+	}
 }