lib9/utf: make safe for automatic build

Add // +build ignore to mkrunetype.c,
rename runetypebody to be .h since it is #included,
delete old runetypebody tables.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5627043

src/lib9/utf/mkrunetype.c

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
+
 /*
  * make is(upper|lower|title|space|alpha)rune and
  * to(upper|lower|title)rune from a UnicodeData.txt file.

src/lib9/utf/runetype.c

@@ -35,4 +35,4 @@ rbsearch(Rune c, Rune *t, int n, int ne)
 	return 0;
 }
 
-#include "runetypebody-6.0.0.c"
+#include "runetypebody-6.0.0.h"