Project: Clarify comment about platform-native compilers.

Modules/CMakeCCompilerId.c.in

@@ -217,7 +217,7 @@
 #  define COMPILER_VERSION_PATCH DEC(_COMPILER_VERSION    % 10)
 # endif
 
-/* This compiler is either not known or is too old to define an
+/* These compilers are either not known or too old to define an
    identification macro.  Try to identify the platform and guess that
    it is the native compiler.  */
 #elif defined(__sgi)

Modules/CMakeCXXCompilerId.cpp.in

@@ -210,7 +210,7 @@
 #  define COMPILER_VERSION_PATCH DEC(_COMPILER_VERSION    % 10)
 # endif
 
-/* This compiler is either not known or is too old to define an
+/* These compilers are either not known or too old to define an
    identification macro.  Try to identify the platform and guess that
    it is the native compiler.  */
 #elif defined(__sgi)