BUG: Fix for spaces in path when loading CMakeTestGNU.c.

Modules/CMakeDetermineCCompiler.cmake

@@ -47,7 +47,7 @@ ENDIF(NOT CMAKE_RANLIB)
 MARK_AS_ADVANCED(CMAKE_RANLIB)
 
 # test to see if the c compiler is gnu
-EXEC_PROGRAM(${CMAKE_C_COMPILER} ARGS -E ${CMAKE_ROOT}/Modules/CMakeTestGNU.c OUTPUT_VARIABLE CMAKE_COMPILER_OUTPUT RETURN_VALUE CMAKE_COMPILER_RETURN)
+EXEC_PROGRAM(${CMAKE_C_COMPILER} ARGS -E "\"${CMAKE_ROOT}/Modules/CMakeTestGNU.c\"" OUTPUT_VARIABLE CMAKE_COMPILER_OUTPUT RETURN_VALUE CMAKE_COMPILER_RETURN)
 IF(NOT CMAKE_COMPILER_RETURN)
   IF("${CMAKE_COMPILER_OUTPUT}" MATCHES ".*THIS_IS_GNU.*" )
     SET(CMAKE_COMPILER_IS_GNUCC 1)