Update CMake to handle ARM64EC with VS Generator (#493)

Author: walbourn

build/CompilerAndLinker.cmake

@@ -18,6 +18,8 @@ elseif(CMAKE_GENERATOR_PLATFORM MATCHES "^[Aa][Rr][Mm]$")
     set(DIRECTX_ARCH arm)
 elseif(CMAKE_GENERATOR_PLATFORM MATCHES "^[Aa][Rr][Mm]64$")
     set(DIRECTX_ARCH arm64)
+elseif(CMAKE_GENERATOR_PLATFORM MATCHES "^[Aa][Rr][Mm]64EC$")
+    set(DIRECTX_ARCH arm64ec)
 elseif(CMAKE_VS_PLATFORM_NAME_DEFAULT MATCHES "^[Ww][Ii][Nn]32$")
     set(DIRECTX_ARCH x86)
 elseif(CMAKE_VS_PLATFORM_NAME_DEFAULT MATCHES "^[Xx]64$")
@@ -26,6 +28,8 @@ elseif(CMAKE_VS_PLATFORM_NAME_DEFAULT MATCHES "^[Aa][Rr][Mm]$")
     set(DIRECTX_ARCH arm)
 elseif(CMAKE_VS_PLATFORM_NAME_DEFAULT MATCHES "^[Aa][Rr][Mm]64$")
     set(DIRECTX_ARCH arm64)
+elseif(CMAKE_VS_PLATFORM_NAME_DEFAULT MATCHES "^[Aa][Rr][Mm]64EC$")
+    set(DIRECTX_ARCH arm64ec)
 endif()
 
 #--- Build with Unicode Win32 APIs per "UTF-8 Everywhere"