Fix bitfield problem when compiling in native mingw

tmk_core/native.mk

@@ -1,3 +1,5 @@
+SYSTEM_TYPE := $(shell gcc -dumpmachine)
+
 CC = gcc
 OBJCOPY = 
 OBJDUMP = 
@@ -14,6 +16,9 @@ COMPILEFLAGS += -funsigned-bitfields
 COMPILEFLAGS += -ffunction-sections
 COMPILEFLAGS += -fdata-sections
 COMPILEFLAGS += -fshort-enums
+ifneq ($(findstring mingw, ${SYSTEM_TYPE}),)
+COMPILEFLAGS += -mno-ms-bitfields
+endif
 
 CFLAGS += $(COMPILEFLAGS)
 CFLAGS += -fno-inline-small-functions