Makefile: Fix shared library build in MinGW. This enables -no-undefined linker flag in mingw toolchain. Previous related commit 4b850954056943be03452c9a2b4bb621d663e40b
diff --git a/makefile_include.mk b/makefile_include.mk
index 0d17cec..dca5c3b 100644
--- a/makefile_include.mk
+++ b/makefile_include.mk
@@ -102,7 +102,7 @@ endif
ifeq ($(PLATFORM), Darwin)
LTM_CFLAGS += -Wno-nullability-completeness
endif
-ifeq ($(PLATFORM), CYGWIN)
+ifneq ($(findstring $(PLATFORM),CYGWIN MINGW32 MINGW64 MSYS),)
LIBTOOLFLAGS += -no-undefined
endif