Get rid of HStringLength.

src/arm/lithium-arm.h

Index: src/arm/lithium-arm.h
diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index 42bec145721734ed6a9d8f1fed3ccb16aa9989ac..c568ad6f95e0d7e98022e853e79707d1cd2b237f 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -175,7 +175,6 @@ class LCodeGen;
   V(StringCharCodeAt)                           \
   V(StringCharFromCode)                         \
   V(StringCompareAndBranch)                     \
-  V(StringLength)                               \
   V(SubI)                                       \
   V(RSubI)                                      \
   V(TaggedToI)                                  \
@@ -2314,19 +2313,6 @@ class LStringCharFromCode: public LTemplateInstruction<1, 1, 0> {
 };
 
 
-class LStringLength: public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LStringLength(LOperand* string) {
-    inputs_[0] = string;
-  }
-
-  LOperand* string() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(StringLength, "string-length")
-  DECLARE_HYDROGEN_ACCESSOR(StringLength)
-};
-
-
 class LCheckFunction: public LTemplateInstruction<0, 1, 0> {
  public:
   explicit LCheckFunction(LOperand* value) {