ARM64: VIXL: Fix breaking changes to ternary operator with Register inputs.

Test: mma art
Change-Id: I33d1e05e47f337f1a9271b35dba9227057cda096
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 9762ee8..368c543 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -1533,7 +1533,9 @@
       HConstant* src_cst = source.GetConstant();
       CPURegister temp;
       if (src_cst->IsZeroBitPattern()) {
-        temp = (src_cst->IsLongConstant() || src_cst->IsDoubleConstant()) ? xzr : wzr;
+        temp = (src_cst->IsLongConstant() || src_cst->IsDoubleConstant())
+            ? Register(xzr)
+            : Register(wzr);
       } else {
         if (src_cst->IsIntConstant()) {
           temp = temps.AcquireW();