Set the correct arch for arm64.

The triple should use aarch64 instead of arm64.

Author: FtZPetruska

cmake/GetTriplet.cmake

@@ -1,10 +1,11 @@
 function(get_host_triplet triplet)
     set(host_arch ${CMAKE_SYSTEM_PROCESSOR})
     if(host_arch STREQUAL "x86")
-        set(host_arch "i686")
-    endif()
-    if(host_arch STREQUAL "amd64")
-        set(host_arch "x86_64")
+        set(host_arch "i686" PARENT_SCOPE)
+    elseif(host_arch STREQUAL "amd64")
+        set(host_arch "x86_64" PARENT_SCOPE)
+    elseif(host_arch STREQUAL "arm64")
+        set(host_arch "aarch64" PARENT_SCOPE)
     endif()
 
     if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
@@ -30,10 +31,11 @@ endfunction()
 function(get_build_triplet triplet)
     set(host_arch ${CMAKE_HOST_SYSTEM_PROCESSOR})
     if(host_arch STREQUAL "x86")
-        set(host_arch "i686")
-    endif()
-    if(host_arch STREQUAL "amd64")
-        set(host_arch "x86_64")
+        set(host_arch "i686" PARENT_SCOPE)
+    elseif(host_arch STREQUAL "amd64")
+        set(host_arch "x86_64" PARENT_SCOPE)
+    elseif(host_arch STREQUAL "arm64")
+        set(host_arch "aarch64" PARENT_SCOPE)
     endif()
 
     if(${CMAKE_HOST_SYSTEM_NAME} STREQUAL "Linux")