Comeau: Remove undocumented support for this compiler

This appears to be from CMake 2.8 era and was undocumented.
Comeau last release 2008.

Modules/CMakeCompilerIdDetection.cmake

@@ -42,11 +42,6 @@ function(compiler_id_detection outvar lang)
 
     # Order is relevant here. For example, compilers which pretend to be
     # GCC must appear before the actual GCC.
-    if ("x${lang}" STREQUAL "xCXX")
-      list(APPEND ordered_compilers
-        Comeau
-      )
-    endif()
     list(APPEND ordered_compilers
       Intel
       IntelLLVM

Modules/Compiler/Comeau-CXX-DetermineCompiler.cmake

@@ -1,7 +0,0 @@
-
-set(_compiler_id_pp_test "defined(__COMO__)")
-
-set(_compiler_id_version_compute "
-  /* __COMO_VERSION__ = VRR */
-# define @PREFIX@COMPILER_VERSION_MAJOR @MACRO_DEC@(__COMO_VERSION__ / 100)
-# define @PREFIX@COMPILER_VERSION_MINOR @MACRO_DEC@(__COMO_VERSION__ % 100)")