Autodetct arm64-linux vs x64-linux

Author: lilleyse

cmake/detect-vcpkg-triplet.cmake

@@ -39,8 +39,11 @@ elseif(APPLE)
         endif()
     endif()
 elseif(LINUX)
-    # Assuming x64 here isn't necessarily correct, but it's the only platform we officially support.
-    set(DETECTED_VCPKG_TRIPLET "x64-linux")
+    if(CMAKE_SYSTEM_PROCESSOR STREQUAL "arm64")
+        set(DETECTED_VCPKG_TRIPLET "arm64-linux")
+    else()
+        set(DETECTED_VCPKG_TRIPLET "x64-linux")
+    endif()
 else()
     set(DETECTED_VCPKG_TRIPLET_ERROR "Cannot guess an appropriate value for VCPKG_TRIPLET because the operating system is unknown. Please set it manually.")
 endif()