patch 8.1.1119: no support for Windows on ARM64.

Problem:    No support for Windows on ARM64.
Solution:   Add ARM64 support (Leendert van Doorn)
diff --git a/src/dosinst.c b/src/dosinst.c
index 2c05cf4..ca74758 100644
--- a/src/dosinst.c
+++ b/src/dosinst.c
@@ -1677,7 +1677,9 @@
 
     printf("Creating an uninstall entry\n");
     sprintf(display_name, "Vim " VIM_VERSION_SHORT
-#ifdef _WIN64
+#ifdef _M_ARM64
+	    " (arm64)"
+#elif _M_X64
 	    " (x64)"
 #endif
 	    );