Tests: Fix RunCMake.VsDotnetSdk with VS >= 17.3 on ARM64

VS 17.3 provides an arm64-native version of the tool, but the test was
looking for the x64 version.

Tests/RunCMake/VsDotnetSdk/VsDotnetSdk.cmake

@@ -6,16 +6,22 @@ project (DotNetSdk CSharp)
 set(CMAKE_DOTNET_TARGET_FRAMEWORK net472)
 set(CMAKE_DOTNET_SDK "Microsoft.NET.Sdk")
 
+if(CMAKE_VS_PLATFORM_NAME STREQUAL "ARM64")
+    set(VS_RT_IDENTIFIER arm64)
+else()
+    set(VS_RT_IDENTIFIER win10-x64)
+endif()
+
 add_library(dotNetSdkLib1 SHARED lib1.cs)
 set_target_properties(dotNetSdkLib1
     PROPERTIES
-        VS_GLOBAL_RuntimeIdentifier win10-x64)
+        VS_GLOBAL_RuntimeIdentifier ${VS_RT_IDENTIFIER})
 
 add_executable(DotNetSdk csharponly.cs)
 target_link_libraries(DotNetSdk dotNetSdkLib1)
 set_target_properties(DotNetSdk
     PROPERTIES
-        VS_GLOBAL_RuntimeIdentifier win10-x64
+        VS_GLOBAL_RuntimeIdentifier ${VS_RT_IDENTIFIER}
 
         VS_DOTNET_REFERENCE_SomeDll
             ${PROJECT_SOURCE_DIR}/SomeDll.dll)