cmd/compile/internal/inline: allow inlining of checkptr arguments

The early return here is meant to suppress inlining of the function
call itself. However, it also suppresses recursing to visit the call
arguments, which are safe to inline.

Change-Id: I75887574c00931cb622277d04a822bc84c29bfa2
Reviewed-on: https://go-review.googlesource.com/c/go/+/543658
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/cmd/compile/internal/inline/inl.go

@@ -863,7 +863,7 @@ func inlnode(callerfn *ir.Func, n ir.Node, bigCaller bool, inlCalls *[]*ir.Inlin
 				if base.Debug.Checkptr != 0 {
 					switch types.ReflectSymName(s) {
 					case "Value.UnsafeAddr", "Value.Pointer":
-						return n
+						n.NoInline = true
 					}
 				}
 			}

test/fixedbugs/issue35073b.go

@@ -0,0 +1,23 @@
+// errorcheck -0 -d=checkptr -m
+
+// Copyright 2020 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.
+
+// Test that we can inline the receiver arguments for
+// reflect.Value.UnsafeAddr/Pointer, even in checkptr mode.
+
+package main
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+func main() {
+	n := 10                      // ERROR "moved to heap: n"
+	m := make(map[string]string) // ERROR "moved to heap: m" "make\(map\[string\]string\) escapes to heap"
+
+	_ = unsafe.Pointer(reflect.ValueOf(&n).Elem().UnsafeAddr()) // ERROR "inlining call"
+	_ = unsafe.Pointer(reflect.ValueOf(&m).Elem().Pointer())    // ERROR "inlining call"
+}