Add missing MODULEXXX macros

Author: wilzbach

std.ddoc

@@ -32,6 +32,9 @@ MODULE2=$(MODULE $2, $1, $+)
 MODULE3=$(MODULE $3, $1, $+)
 MODULE4=$(MODULE $4, $1, $+)
 MODULE5=$(MODULE $5, $1, $+)
+MODULE6=$(MODULE $6, $1, $+)
+MODULE7=$(MODULE $7, $1, $+)
+MODULE8=$(MODULE $8, $1, $+)
 PACKAGE=$1$(ITEMIZE $+)
 PACKAGE_NAME=$(T h7,$(D $1))
 JOIN_LINE_TAIL=$(JOIN_LINE $+)