ctkMacroBuildLib - On Linux, set -fPIC compile flag if build statically

CMake/ctkMacroBuildLib.cmake

@@ -147,6 +147,13 @@ MACRO(ctkMacroBuildLib)
     SET_TARGET_PROPERTIES(${lib_name} PROPERTIES ${CTK_LIBRARY_PROPERTIES})
   ENDIF()
   SET_TARGET_PROPERTIES(${lib_name} PROPERTIES CTK_LIB_TARGET_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+  
+  # Library properties specific to STATIC build
+  IF(MY_LIBRARY_TYPE STREQUAL "STATIC")
+    IF(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
+      SET_TARGET_PROPERTIES(${lib_name} PROPERTIES COMPILE_FLAGS "-fPIC")
+    ENDIF()
+  ENDIF()
 
   # Install rules
   IF(MY_LIBRARY_TYPE STREQUAL "SHARED")