cmd/compile: fix println()

println with no arguments accidentally doesn't print a newline.

Introduced at CL 55097

Fixes #21808

Change-Id: I9fc7b4271b9b31e4c9b6078f055195dc3907b62c
Reviewed-on: https://go-review.googlesource.com/62390
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/test/fixedbugs/issue21808.go b/test/fixedbugs/issue21808.go
new file mode 100644
index 0000000000..d146200eae
--- /dev/null
+++ b/test/fixedbugs/issue21808.go
@@ -0,0 +1,17 @@
+// run
+
+// Copyright 2017 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.
+
+// Make sure println() prints a blank line.
+
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("A")
+	println()
+	fmt.Println("B")
+}