cmake: use IMPORTED targets for libc and ld.so

Author: fw-immunant

runtime/libia2/CMakeLists.txt

@@ -145,8 +145,13 @@ if(LIBIA2_AARCH64)
         DEPENDS ${LD_LINUX_PATH}
         COMMENT "Copying ld-linux-aarch64.so.1"
     )
-    target_link_libraries(libia2 PUBLIC "${CMAKE_CURRENT_BINARY_DIR}/ld-linux-aarch64.so.1")
-    add_custom_target(libc-ia2 DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libc.so.6" DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/ld-linux-aarch64.so.1")
+    add_library(libc SHARED IMPORTED)
+    set_property(TARGET libc PROPERTY IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/libc.so.6")
+    target_link_libraries(libia2 PUBLIC libc)
+    add_library(ld-linux SHARED IMPORTED)
+    set_property(TARGET ld-linux PROPERTY IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/ld-linux-aarch64.so.1")
+    target_link_libraries(libia2 PUBLIC ld-linux)
+    add_custom_target(libc-ia2 DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libc.so.6" "${CMAKE_CURRENT_BINARY_DIR}/ld-linux-aarch64.so.1")
 else()
     add_custom_target(libc-ia2 DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libc.so.6")
 endif()