Update prebuilts to go1.8rc1 ab/3640477

Bug: 32982374
Test: m -j blueprint_tools
Change-Id: I09e8bcb7136e524dce01bed6fd70276136ad452b
diff --git a/test/fixedbugs/issue17551.go b/test/fixedbugs/issue17551.go
new file mode 100644
index 0000000..b8751ab
--- /dev/null
+++ b/test/fixedbugs/issue17551.go
@@ -0,0 +1,21 @@
+// compile
+
+// Copyright 2016 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.
+
+// Issue 17551: inrange optimization failed to preserve type information.
+
+package main
+
+import "fmt"
+
+func main() {
+	_, x := X()
+	fmt.Printf("x = %v\n", x)
+}
+
+func X() (i int, ok bool) {
+	ii := int(1)
+	return ii, 0 <= ii && ii <= 0x7fffffff
+}