windows/Makefile: Support freezing modules.
Alter the build flags as needed to support freezing modules with a
manifest.  This makes freezing works just like it does for e.g. the unix
port.
@@ -59,4 +59,9 @@ SRC_QSTR += $(SRC_C)
# SRC_QSTR
SRC_QSTR_AUTO_DEPS +=
+ifneq ($(FROZEN_MANIFEST),)
+CFLAGS += -DMICROPY_QSTR_EXTRA_POOL=mp_qstr_frozen_const_pool -DMICROPY_MODULE_FROZEN_MPY=1 -DMPZ_DIG_SIZE=16
+MPY_CROSS_FLAGS += -mcache-lookup-bc
+endif
+
include $(TOP)/py/mkrules.mk
