Use static libgcc and libstdc++ only on linux.

iguana/exchanges/CMakeLists.txt

@@ -26,5 +26,9 @@ add_definitions(-DIGUANA_MAXPACKETSIZE=1572864)
 add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 include_directories("${CMAKE_SOURCE_DIR}/includes")
 endif()
-target_link_libraries(marketmaker-testnet ${MM_LIBS} etomiclib-testnet -static-libgcc -static-libstdc++)
-target_link_libraries(marketmaker-mainnet ${MM_LIBS} etomiclib-mainnet -static-libgcc -static-libstdc++)
+target_link_libraries(marketmaker-testnet ${MM_LIBS} etomiclib-testnet)
+target_link_libraries(marketmaker-mainnet ${MM_LIBS} etomiclib-mainnet)
+if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
+target_link_libraries(marketmaker-mainnet -static-libgcc -static-libstdc++)
+target_link_libraries(marketmaker-testnet -static-libgcc -static-libstdc++)
+endif()