Replace a few std::vector with ArenaVector in Mir2Lir.

Change-Id: I7867d60afc60f57cdbbfd312f02883854d65c805
diff --git a/compiler/dex/quick/x86/target_x86.cc b/compiler/dex/quick/x86/target_x86.cc
index c4adb09..8f97d1e 100755
--- a/compiler/dex/quick/x86/target_x86.cc
+++ b/compiler/dex/quick/x86/target_x86.cc
@@ -1051,10 +1051,10 @@
     }
 
     for (LIR *p = const_vectors_; p != nullptr; p = p->next) {
-      PushWord(&code_buffer_, p->operands[0]);
-      PushWord(&code_buffer_, p->operands[1]);
-      PushWord(&code_buffer_, p->operands[2]);
-      PushWord(&code_buffer_, p->operands[3]);
+      Push32(&code_buffer_, p->operands[0]);
+      Push32(&code_buffer_, p->operands[1]);
+      Push32(&code_buffer_, p->operands[2]);
+      Push32(&code_buffer_, p->operands[3]);
     }
   }