Do not add values to HGraph in Lithium.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 34c3155c65a99e61f4b93fc1b6c9b06ac8ab6b1a..ecf738f913d2d2ea35a6b44f30a010055dc8ee6b 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -5690,6 +5690,11 @@ void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
 }
 
 
+void LCodeGen::DoDummy(LDummy* instr) {
+  // Nothing to see here, move on!
+}
+
+
 void LCodeGen::DoDummyUse(LDummyUse* instr) {
   // Nothing to see here, move on!
 }