cmake: detect ARM64EC

VisualC/pkg-support/cmake/sdl3-config.cmake

@@ -32,7 +32,7 @@ set(SDL3_FOUND TRUE)
 
 if(SDL_CPU_X86)
     set(_sdl_arch_subdir "x86")
-elseif(SDL_CPU_X64)
+elseif(SDL_CPU_X64 OR SDL_CPU_ARM64EC)
     set(_sdl_arch_subdir "x64")
 elseif(SDL_CPU_ARM64)
     set(_sdl_arch_subdir "arm64")

cmake/sdlcpu.cmake

@@ -34,12 +34,13 @@ function(SDL_DetectTargetCPUArchitectures DETECTED_ARCHS)
 
   set(arch_check_ARM32 "defined(__arm__) || defined(_M_ARM)")
   set(arch_check_ARM64 "defined(__aarch64__) || defined(_M_ARM64)")
+  set(arch_check_ARM64EC "defined(_M_ARM64EC)")
   set(arch_check_EMSCRIPTEN "defined(__EMSCRIPTEN__)")
   set(arch_check_LOONGARCH64 "defined(__loongarch64)")
   set(arch_check_POWERPC32 "(defined(__PPC__) || defined(__powerpc__)) && !defined(__powerpc64__)")
   set(arch_check_POWERPC64 "defined(__PPC64__) || defined(__powerpc64__)")
   set(arch_check_X86 "defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__) ||defined( __i386) || defined(_M_IX86)")
-  set(arch_check_X64 "defined(__amd64__) || defined(__amd64) || defined(__x86_64__) || defined(__x86_64) || defined(_M_X64) || defined(_M_AMD64)")
+  set(arch_check_X64 "(defined(__amd64__) || defined(__amd64) || defined(__x86_64__) || defined(__x86_64) || defined(_M_X64) || defined(_M_AMD64)) && !defined(_M_ARM64EC)")
 
   set(src_vars "")
   set(src_main "")