cmd/compile: fix missing case for shape double-check function

Missing case types.TUNSAFEPTR in parameterizedBy().

Also realized there was the same missing case in the type substituter
(*Tsubster).Typ().

Fixes #48103

Change-Id: If71f1a6ef80932f0e2120d4c18b39a30189fd8fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/346669
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>

src/cmd/compile/internal/noder/stencil.go

@@ -1917,7 +1917,7 @@ func parameterizedBy1(t *types.Type, params []*types.Type, visited map[*types.Ty
 
 	case types.TINT, types.TINT8, types.TINT16, types.TINT32, types.TINT64,
 		types.TUINT, types.TUINT8, types.TUINT16, types.TUINT32, types.TUINT64,
-		types.TUINTPTR, types.TBOOL, types.TSTRING, types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128:
+		types.TUINTPTR, types.TBOOL, types.TSTRING, types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128, types.TUNSAFEPTR:
 		return true
 
 	case types.TUNION:

src/cmd/compile/internal/typecheck/subr.go

@@ -1189,7 +1189,7 @@ func (ts *Tsubster) typ1(t *types.Type) *types.Type {
 		}
 	case types.TINT, types.TINT8, types.TINT16, types.TINT32, types.TINT64,
 		types.TUINT, types.TUINT8, types.TUINT16, types.TUINT32, types.TUINT64,
-		types.TUINTPTR, types.TBOOL, types.TSTRING, types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128:
+		types.TUINTPTR, types.TBOOL, types.TSTRING, types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128, types.TUNSAFEPTR:
 		newt = t.Underlying()
 	case types.TUNION:
 		nt := t.NumTerms()

test/typeparam/issue48013.go

@@ -0,0 +1,39 @@
+// run -gcflags=-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 main
+
+import (
+	"fmt"
+	"unsafe"
+)
+
+type S[T any] struct {
+	val T
+}
+
+// Test type substitution where base type is unsafe.Pointer
+type U[T any] unsafe.Pointer
+
+func test[T any]() T {
+	var q U[T]
+	var v struct {
+		// Test derived type that contains an unsafe.Pointer
+		p   unsafe.Pointer
+		val T
+	}
+	_ = q
+	return v.val
+}
+
+func main() {
+	want := 0
+	got := test[int]()
+	if got != want {
+		panic(fmt.Sprintf("got %f, want %f", got, want))
+	}
+
+}