link mingw libstdc++ and libgcc libs statically so users dont need mingw installed to use mingw builds

CMakeLists.txt

@@ -1026,9 +1026,12 @@ elseif(WIN32)
 			set(OPENIMAGEIO_LIBPATH ${OPENIMAGEIO}/lib)
 			set(OPENIMAGEIO_DEFINITIONS)
 		endif()
-
+		
 		set(PLATFORM_LINKFLAGS "-Xlinker --stack=2097152")
 
+		# for re-distrobution, so users dont need mingw installed
+		set(PLATFORM_LINKFLAGS "${PLATFORM_LINKFLAGS} -static-libgcc -static-libstdc++")
+
 	endif()
 
 	# used in many places so include globally, like OpenGL

build_files/scons/config/win32-mingw-config.py

@@ -190,6 +190,9 @@ LLIBS = ['-lshell32', '-lshfolder', '-lgdi32', '-lmsvcrt', '-lwinmm', '-lmingw32
 
 PLATFORM_LINKFLAGS = ['-Xlinker', '--stack=2097152']
 
+# for re-distrobution, so users dont need mingw installed
+PLATFORM_LINKFLAGS += ["-static-libgcc", "-static-libstdc++"]
+
 BF_DEBUG = False
 BF_DEBUG_CCFLAGS= ['-g', '-D_DEBUG']