Update CMakeLists.txt

Make IrrXml dynamic only on BSD

contrib/irrXML/CMakeLists.txt

@@ -13,7 +13,11 @@ if ( MSVC )
   ADD_DEFINITIONS( -D_CRT_SECURE_NO_WARNINGS )
 endif ( MSVC )
 
-add_library(IrrXML ${IrrXML_SRCS})
+IF(CMAKE_SYSTEM_NAME MATCHES "(Darwin|FreeBSD)")
+  add_library(IrrXML ${IrrXML_SRCS})
+ELSE()
+  add_library(IrrXML STATIC ${IrrXML_SRCS})
+ENDIF()
 set(IRRXML_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}" CACHE INTERNAL "IrrXML_Include" )
 set(IRRXML_LIBRARY "IrrXML" CACHE INTERNAL "IrrXML" )