Fix up compiling on DD version

src/Makefile

@@ -177,6 +177,7 @@ include win32/Makefile.cfg
 endif #ifdef MINGW
 
 ifdef MINGW64
+MINGW=1
 NONX86=1
 include win32/Makefile.cfg
 endif #ifdef MINGW64
@@ -715,7 +716,6 @@ $(BIN)/s_openal.so: $(OBJDIR)/s_openal.o
 	-$(MKDIR) $(BIN)
 	@echo Linking S_OpenAL.so...
 	$(CC) --shared $^ -o $@ -g --nostartfiles -lm -lopenal
-
 endif
 
 else

src/Makefile.cfg

@@ -235,6 +235,7 @@ ifndef LINUX
 ifndef FREEBSD
 ifndef CYGWIN32
 ifndef MINGW
+ifndef MINGW64
 ifndef SDL
 ifndef NDS
 ifndef DUMMY
@@ -252,6 +253,7 @@ endif
 endif
 endif
 endif
+endif
 
 #determine the interface directory (where you put all i_*.c)
 i_cdmus_o=$(OBJDIR)/i_cdmus.o

src/win32/Makefile.cfg

@@ -26,7 +26,7 @@ ifndef NOASM
 	USEASM=1
 endif
 
-ifdef MINGW
+ifdef MINGW #miniupnc is broken with MINGW64
 	HAVE_MINIUPNPC=1
 endif