cmd/gc: fix <-<-expr

The temporary-introducing pass was not recursing
into the argumnt of a receive operation.

Fixes issue 8011.

LGTM=r
R=golang-codereviews, r
CC=golang-codereviews, iant, khr
https://codereview.appspot.com/91540043

1 files changed, 18 insertions, 0 deletions

diff --git a/test/fixedbugs/issue8011.go b/test/fixedbugs/issue8011.go
new file mode 100644
index 000000000..b966174c0
--- /dev/null
+++ b/test/fixedbugs/issue8011.go
@@ -0,0 +1,18 @@
+// run
+
+// Copyright 2014 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 main() {
+	c := make(chan chan int, 1)
+	c1 := make(chan int, 1)
+	c1 <- 42
+	c <- c1
+	x := <-<-c
+	if x != 42 {
+		println("BUG:", x, "!= 42")
+	}
+}