BUG: Need to duplicate some information from CMakeCCompiler to support C++-only projects.

Modules/CMakeCXXCompiler.cmake.in

@@ -1,9 +1,22 @@
 SET(CMAKE_CXX_COMPILER "@CMAKE_CXX_COMPILER@")
 SET(CMAKE_CXX_COMPILER_ARG1 "@CMAKE_CXX_COMPILER_ARG1@")
+SET(CMAKE_AR "@CMAKE_AR@")
+SET(CMAKE_RANLIB "@CMAKE_RANLIB@")
 SET(CMAKE_COMPILER_IS_GNUCXX @CMAKE_COMPILER_IS_GNUCXX@)
 SET(CMAKE_CXX_COMPILER_LOADED 1)
-SET(CMAKE_COMPILER_IS_GNUCXX_RUN 1)
+SET(CMAKE_COMPILER_IS_MINGW @CMAKE_COMPILER_IS_MINGW@)
+SET(CMAKE_COMPILER_IS_CYGWIN @CMAKE_COMPILER_IS_CYGWIN@)
+IF(CMAKE_COMPILER_IS_CYGWIN)
+  SET(CYGWIN 1)
+  SET(UNIX 1)
+ENDIF(CMAKE_COMPILER_IS_CYGWIN)
+
+SET(CMAKE_CXX_COMPILER_ENV_VAR "CXX")
 
+IF(CMAKE_COMPILER_IS_MINGW)
+  SET(MINGW 1)
+ENDIF(CMAKE_COMPILER_IS_MINGW)
+SET(CMAKE_COMPILER_IS_GNUCXX_RUN 1)
 SET(CMAKE_CXX_IGNORE_EXTENSIONS inl;h;H;o;O;obj;OBJ;def;DEF;rc;RC)
 SET(CMAKE_CXX_SOURCE_FILE_EXTENSIONS C;M;c++;cc;cpp;cxx;m;mm)
 SET(CMAKE_CXX_LINKER_PREFERENCE Prefered)
@@ -12,4 +25,6 @@ IF(UNIX)
 ELSE(UNIX)
   SET(CMAKE_CXX_OUTPUT_EXTENSION .obj)
 ENDIF(UNIX)
-SET(CMAKE_CXX_COMPILER_ENV_VAR "CXX")
+# save the size of void* in case where cache is removed
+# and the this file is still around
+SET(CMAKE_SIZEOF_VOID_P @CMAKE_SIZEOF_VOID_P@)