Fix LoadFieldByIndex to take mutable heap-numbers into account.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 1e6ac19bf7f42dcedcd7fe1a953168967002bdfc..cf6b97007d292aca894c9baf23ec0229cb5de8a5 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -7499,6 +7499,7 @@ class HLoadFieldByIndex V8_FINAL : public HTemplateInstruction<2> {
                     HValue* index) {
     SetOperandAt(0, object);
     SetOperandAt(1, index);
+    SetChangesFlag(kNewSpacePromotion);
     set_representation(Representation::Tagged());
   }