Don't want when using a (signed) char as an array subscript.

src/build/Common.gmake

@@ -384,7 +384,7 @@ endif
 ifdef DEBUG
  CFLAGS	+=	-ggdb
  CFLAGS	+=	-D_DEBUG
- CFLAGS +=	-Wall
+ CFLAGS +=	-Wall -Wno-char-subscripts
 else # RELEASE
  # -finline functions breaks the baja build badly.
  # This also means that -O3 won't work either.