[release-branch.go1.9] go1.9rc1

Change-Id: I6251fc128990f9494a0b037cabb24ada5eabb6b5
Reviewed-on: https://go-review.googlesource.com/50951
Run-TryBot: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>

VERSION

diff --git a/VERSION b/VERSION
new file mode 100644
index 0000000..e71f694
--- /dev/null
+++ b/VERSION
@@ -0,0 +1 @@
+go1.9rc1
\ No newline at end of file