Fix accidental pass-by-value

Change-Id: I245111eabb43368875c1215ca4f3a1f1918492fe
diff --git a/compiler/optimizing/register_allocation_resolver.cc b/compiler/optimizing/register_allocation_resolver.cc
index 8f5a2a8..3450286 100644
--- a/compiler/optimizing/register_allocation_resolver.cc
+++ b/compiler/optimizing/register_allocation_resolver.cc
@@ -36,7 +36,7 @@
                                          size_t float_spill_slots,
                                          size_t double_spill_slots,
                                          size_t catch_phi_spill_slots,
-                                         const ArenaVector<LiveInterval*> temp_intervals) {
+                                         const ArenaVector<LiveInterval*>& temp_intervals) {
   size_t spill_slots = int_spill_slots
                      + long_spill_slots
                      + float_spill_slots
diff --git a/compiler/optimizing/register_allocation_resolver.h b/compiler/optimizing/register_allocation_resolver.h
index 16a8a87..6ceb9bc 100644
--- a/compiler/optimizing/register_allocation_resolver.h
+++ b/compiler/optimizing/register_allocation_resolver.h
@@ -51,7 +51,7 @@
                size_t float_spill_slots,
                size_t double_spill_slots,
                size_t catch_phi_spill_slots,
-               const ArenaVector<LiveInterval*> temp_intervals);
+               const ArenaVector<LiveInterval*>& temp_intervals);
 
  private:
   // Connect adjacent siblings within blocks, and resolve inputs along the way.