Fix RegisterAllocationData::ResetSpillState

Bug: chromium:1014607
Change-Id: Ifcd1ce17fb1f95965355a4e3f63bdc78fa88042f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1865613
Auto-Submit: David Benjamin <davidben@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64338}

src/compiler/backend/register-allocator.h

@@ -335,7 +335,11 @@ class RegisterAllocationData final : public ZoneObject {
     return result;
   }
 
-  void ResetSpillState() { spill_state_.clear(); }
+  void ResetSpillState() {
+    for (auto& state : spill_state_) {
+      state.clear();
+    }
+  }
 
   TickCounter* tick_counter() { return tick_counter_; }