Handle targets in the LINK_LIBRARIES of try_compile.

Imported targets are re-exported so that they can be used by the
try_compile generated code with target_link_libraries.

This makes the use of the cmake_expand_imported_targets macro
obsolete. The macro is not able to expand the generator expressions
which may appear in the IMPORTED_LINK_INTERFACE_LIBRARIES content.
Instead it just sees them as 'not a target'.

Modules/CheckCSourceCompiles.cmake

@@ -24,7 +24,6 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
-include("${CMAKE_CURRENT_LIST_DIR}/CMakeExpandImportedTargets.cmake")
 
 
 macro(CHECK_C_SOURCE_COMPILES SOURCE VAR)
@@ -43,10 +42,8 @@ macro(CHECK_C_SOURCE_COMPILES SOURCE VAR)
     set(MACRO_CHECK_FUNCTION_DEFINITIONS
       "-D${VAR} ${CMAKE_REQUIRED_FLAGS}")
     if(CMAKE_REQUIRED_LIBRARIES)
-      # this one translates potentially used imported library targets to their files on disk
-      CMAKE_EXPAND_IMPORTED_TARGETS(_ADJUSTED_CMAKE_REQUIRED_LIBRARIES  LIBRARIES  ${CMAKE_REQUIRED_LIBRARIES} CONFIGURATION "${CMAKE_TRY_COMPILE_CONFIGURATION}")
       set(CHECK_C_SOURCE_COMPILES_ADD_LIBRARIES
-        "-DLINK_LIBRARIES:STRING=${_ADJUSTED_CMAKE_REQUIRED_LIBRARIES}")
+        LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
     else()
       set(CHECK_C_SOURCE_COMPILES_ADD_LIBRARIES)
     endif()
@@ -64,8 +61,8 @@ macro(CHECK_C_SOURCE_COMPILES SOURCE VAR)
       ${CMAKE_BINARY_DIR}
       ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c
       COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+      ${CHECK_C_SOURCE_COMPILES_ADD_LIBRARIES}
       CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
-      "${CHECK_C_SOURCE_COMPILES_ADD_LIBRARIES}"
       "${CHECK_C_SOURCE_COMPILES_ADD_INCLUDES}"
       OUTPUT_VARIABLE OUTPUT)