CMakeDetermine*Compiler: Add hook to save custom compiler information

Provide a way for Platform/<os>-Determine-<lang>.cmake modules to save
platform-specific information about the compiler in the configured
CMake<lang>Compiler.cmake modules.

Modules/CMakeCCompiler.cmake.in

@@ -59,6 +59,7 @@ if(CMAKE_C_CL_SHOWINCLUDES_PREFIX)
   set(CMAKE_CL_SHOWINCLUDES_PREFIX "${CMAKE_C_CL_SHOWINCLUDES_PREFIX}")
 endif()
 
+@CMAKE_C_COMPILER_CUSTOM_CODE@
 @CMAKE_C_SYSROOT_FLAG_CODE@
 @CMAKE_C_OSX_DEPLOYMENT_TARGET_FLAG_CODE@
 

Modules/CMakeCXXCompiler.cmake.in

@@ -60,6 +60,7 @@ if(CMAKE_CXX_CL_SHOWINCLUDES_PREFIX)
   set(CMAKE_CL_SHOWINCLUDES_PREFIX "${CMAKE_CXX_CL_SHOWINCLUDES_PREFIX}")
 endif()
 
+@CMAKE_CXX_COMPILER_CUSTOM_CODE@
 @CMAKE_CXX_SYSROOT_FLAG_CODE@
 @CMAKE_CXX_OSX_DEPLOYMENT_TARGET_FLAG_CODE@
 

Modules/CMakeFortranCompiler.cmake.in

@@ -54,6 +54,8 @@ if(CMAKE_Fortran_LIBRARY_ARCHITECTURE)
   set(CMAKE_LIBRARY_ARCHITECTURE "@CMAKE_Fortran_LIBRARY_ARCHITECTURE@")
 endif()
 
+@CMAKE_Fortran_COMPILER_CUSTOM_CODE@
+
 set(CMAKE_Fortran_IMPLICIT_LINK_LIBRARIES "@CMAKE_Fortran_IMPLICIT_LINK_LIBRARIES@")
 set(CMAKE_Fortran_IMPLICIT_LINK_DIRECTORIES "@CMAKE_Fortran_IMPLICIT_LINK_DIRECTORIES@")
 set(CMAKE_Fortran_IMPLICIT_LINK_FRAMEWORK_DIRECTORIES "@CMAKE_Fortran_IMPLICIT_LINK_FRAMEWORK_DIRECTORIES@")