Allow void to get in ARM64ReturnLocation.

It can now be called with it.

Change-Id: Idd10dbf5c9cb5f418504cb4c9252930e6eb4942d
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 689a35a..2f607f7 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -84,7 +84,6 @@
 }
 
 Location ARM64ReturnLocation(Primitive::Type return_type) {
-  DCHECK_NE(return_type, Primitive::kPrimVoid);
   // Note that in practice, `LocationFrom(x0)` and `LocationFrom(w0)` create the
   // same Location object, and so do `LocationFrom(d0)` and `LocationFrom(s0)`,
   // but we use the exact registers for clarity.
@@ -94,6 +93,8 @@
     return LocationFrom(d0);
   } else if (return_type == Primitive::kPrimLong) {
     return LocationFrom(x0);
+  } else if (return_type == Primitive::kPrimVoid) {
+    return Location::NoLocation();
   } else {
     return LocationFrom(w0);
   }