[llvm-dlltool] Mention arm64 in the lists of architecture alternatives

This was missed in SVN r310223 when arm64 support was added.

Differential Revision: https://reviews.llvm.org/D37588

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312776 91177308-0d34-0410-b5e6-96231b3b80d8

Author: mstorsjo

lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp

@@ -99,13 +99,13 @@ int llvm::dlltoolDriverMain(llvm::ArrayRef<const char *> ArgsArr) {
   if (Args.hasArgNoClaim(OPT_INPUT) ||
       (!Args.hasArgNoClaim(OPT_d) && !Args.hasArgNoClaim(OPT_l))) {
     Table.PrintHelp(outs(), ArgsArr[0], "dlltool", false);
-    llvm::outs() << "\nTARGETS: i386, i386:x86-64, arm\n";
+    llvm::outs() << "\nTARGETS: i386, i386:x86-64, arm, arm64\n";
     return 1;
   }
 
   if (!Args.hasArgNoClaim(OPT_m) && Args.hasArgNoClaim(OPT_d)) {
     llvm::errs() << "error: no target machine specified\n"
-                 << "supported targets: i386, i386:x86-64, arm\n";
+                 << "supported targets: i386, i386:x86-64, arm, arm64\n";
     return 1;
   }