VS10: Do not set the TargetMachine when detecting the compiler

The Microsoft linker is intelligent enough to detect the target
machine type depending on the input files. This allows us to
get the target architecture from the compiler instead of
maintaining the mapping to the platform name.

Modules/CMakeDetermineCompilerId.cmake

@@ -126,15 +126,8 @@ Id flags: ${testflags}
       set(v 6)
       set(ext dsp)
     endif()
-    if("${id_arch}" STREQUAL "x64")
-      set(id_machine_10 MachineX64)
-    elseif("${id_arch}" STREQUAL "Itanium")
-      set(id_machine_10 MachineIA64)
+    if("${id_arch}" STREQUAL "Itanium")
       set(id_arch ia64)
-    elseif("${id_arch}" STREQUAL "ARM")
-      set(id_machine_10 MachineARM)
-    else()
-      set(id_machine_10 MachineX86)
     endif()
     if(CMAKE_VS_PLATFORM_TOOLSET)
       set(id_toolset "<PlatformToolset>${CMAKE_VS_PLATFORM_TOOLSET}</PlatformToolset>")

Modules/CompilerId/VS-10.vcxproj.in

@@ -40,7 +40,6 @@
     <Link>
       <GenerateDebugInformation>false</GenerateDebugInformation>
       <SubSystem>Console</SubSystem>
-      <TargetMachine>@id_machine_10@</TargetMachine>
     </Link>
     <PostBuildEvent>
       <Command>for %%i in (@id_cl@) do %40echo CMAKE_@id_lang@_COMPILER=%%~$PATH:i</Command>