lib9/fmt: do not put a main symbol into lib9.a

Fixes #4143.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6541064

diff --git a/src/lib9/fmt/test.c b/src/lib9/fmt/test.c
index 1710c5e484ed69cc0641d407d9d55ef6ece84d1c..d82ff78baf48f10b140ad8dcf07df3ac9f105ef9 100644 (file)
--- a/src/lib9/fmt/test.c
+++ b/src/lib9/fmt/test.c
@@ -1,3 +1,5 @@
+// +build ignore
+
 /*
  * The authors of this software are Rob Pike and Ken Thompson,
  * with contributions from Mike Burrows and Sean Dorward.