cmd/compile: fix inlining labeled switch statements

CL 357649 fixes inlining labeled FOR/RANGE loops,
we should do same translation for inlined SWITCH's label

Fixes #49145

Change-Id: I9a6f365f57e974271a1eb279b38e81f9b5148788
Reviewed-on: https://go-review.googlesource.com/c/go/+/358315
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>

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

@@ -1285,18 +1285,24 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 	ir.EditChildren(m, subst.edit)
 
 	if subst.newclofn == nil {
-		// Translate any label on FOR or RANGE loops
-		if m.Op() == ir.OFOR {
+		// Translate any label on FOR, RANGE loops or SWITCH
+		switch m.Op() {
+		case ir.OFOR:
 			m := m.(*ir.ForStmt)
 			m.Label = translateLabel(m.Label)
 			return m
+
+		case ir.ORANGE:
+			m := m.(*ir.RangeStmt)
+			m.Label = translateLabel(m.Label)
+			return m
+
+		case ir.OSWITCH:
+			m := m.(*ir.SwitchStmt)
+			m.Label = translateLabel(m.Label)
+			return m
 		}
 
-		if m.Op() == ir.ORANGE {
-			m := m.(*ir.RangeStmt)
-			m.Label = translateLabel(m.Label)
-			return m
-		}
 	}
 
 	switch m := m.(type) {

test/fixedbugs/issue49145.go

@@ -0,0 +1,27 @@
+// run
+
+// 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
+
+func f(j int) {
+loop:
+	switch j {
+	case 1:
+		break loop
+	default:
+		println(j)
+	}
+}
+
+func main() {
+loop:
+	for j := 0; j < 5; j++ {
+		f(j)
+		if j == 3 {
+			break loop
+		}
+	}
+}

test/fixedbugs/issue49145.out

@@ -0,0 +1,3 @@
+0
+2
+3