Don't assign safepoint at the definition to the definition's live-range.

runtime/vm/locations.h

Index: runtime/vm/locations.h
diff --git a/runtime/vm/locations.h b/runtime/vm/locations.h
index 91ed897d2632a5ee0aff5bd047e2d12f37fc05a5..9b5b841835d57685e7b34a8c9b3167dbc97f7a46 100644
--- a/runtime/vm/locations.h
+++ b/runtime/vm/locations.h
@@ -445,6 +445,17 @@ class RegisterSet : public ValueObject {
     }
   }
 
+  bool Contains(Location loc) {
+    if (loc.IsRegister()) {
+      return ContainsRegister(loc.reg());
+    } else if (loc.IsFpuRegister()) {
+      return ContainsFpuRegister(loc.fpu_reg());
+    } else {
+      UNREACHABLE();
+      return false;
+    }
+  }
+
   void DebugPrint() {
     for (intptr_t i = 0; i < kNumberOfCpuRegisters; i++) {
       Register r = static_cast<Register>(i);