cmd/compile: make sure that the names created for instantiated type are the same

Now we have two functions that create names for instantiated types.
They are inconsistent when dealing with byte/rune type.

This CL makes instTypeName2 reuse the code of typecheck.InstTypeName

Fixes #48198

Change-Id: I4c216b532cba6618ef9b63fd0b76e8f1c0ed7a75
Reviewed-on: https://go-review.googlesource.com/c/go/+/347491
Reviewed-by: Dan Scales <danscales@google.com>
Trust: Dan Scales <danscales@google.com>
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/test/typeparam/issue48198.go b/test/typeparam/issue48198.go
new file mode 100644
index 0000000000..1d7e44e0c4
--- /dev/null
+++ b/test/typeparam/issue48198.go
@@ -0,0 +1,22 @@
+// compile -G=3
+
+// Copyright 2021 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.
+package p
+
+type Foo[T any] struct {
+}
+
+func (foo Foo[T]) Get()  {
+}
+
+var(
+	_ = Foo[byte]{}
+	_ = Foo[[]byte]{}
+	_ = Foo[map[byte]rune]{}
+
+	_ = Foo[rune]{}
+	_ = Foo[[]rune]{}
+	_ = Foo[map[rune]byte]{}
+)