Work with newer Bazel too

Change-Id: I1b13cd9661903afc2130e13699ebc8c0c39c3a0d
diff --git a/tools/bazel.rc b/tools/bazel.rc
index 1b77288..5ea0fcf 100644
--- a/tools/bazel.rc
+++ b/tools/bazel.rc
@@ -9,6 +9,8 @@
 # TODO(Brian): Fix Bazel so this actually does something again...
 build --hdrs_check=strict
 
+build --crosstool_top=//tools/cpp:toolchain
+
 # Show paths to a few more than just 1 target.
 build --show_result 15
 # Dump the output of the failing test to stdout.