include: add a README file

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9392049

diff --git a/include/README b/include/README
new file mode 100644 (file)
index 0000000..b8fb523
--- /dev/null
+++ b/include/README
@@ -0,0 +1,6 @@
+The header files under this directory are strictly internal to the gc
+toolchain, so please don't copy them to the system include file
+directory (/usr/include, /usr/local/include, etc.)
+
+Also note that they must be kept as is in $GOROOT/include, or cmd/dist
+will malfunction.