Use HOSTCC for seting up the syscall list

Makefile

@@ -104,7 +104,7 @@ endif
 	fi
 	@cd $(TOPDIR); \
 	set -x -e; \
-	TOPDIR=. CC="$(CC)" /bin/sh extra/scripts/gen_bits_syscall_h.sh > include/bits/sysnum.h.new; \
+	TOPDIR=. CC="$(HOSTCC)" /bin/sh extra/scripts/gen_bits_syscall_h.sh > include/bits/sysnum.h.new; \
 	if cmp include/bits/sysnum.h include/bits/sysnum.h.new >/dev/null 2>&1; then \
 		$(RM) include/bits/sysnum.h.new; \
 	else \