BUG: Need to install CMakeCXXCompilerId.cpp so that C++ compiler identification works in an install tree.

Modules/CMakeLists.txt

@@ -1,6 +1,7 @@
 # just install the modules
 SUBDIRS(Platform)
 INSTALL_FILES(${CMAKE_DATA_DIR}/Modules .*\\.cmake$)
+INSTALL_FILES(${CMAKE_DATA_DIR}/Modules .*\\.cpp$)
 INSTALL_FILES(${CMAKE_DATA_DIR}/Modules .*\\.cxx$)
 INSTALL_FILES(${CMAKE_DATA_DIR}/Modules .*\\.in$)
 INSTALL_FILES(${CMAKE_DATA_DIR}/Modules .*\\.c$)