Get rid of HStringLength.

src/mips/lithium-mips.h

Index: src/mips/lithium-mips.h
diff --git a/src/mips/lithium-mips.h b/src/mips/lithium-mips.h
index d4735ce682fa04f2063f2b3b26c06e8f65eb9770..44c909ea766f2a3f5603a1118c55e57ca3dd6cba 100644
--- a/src/mips/lithium-mips.h
+++ b/src/mips/lithium-mips.h
@@ -174,7 +174,6 @@ class LCodeGen;
   V(StringCharCodeAt)                           \
   V(StringCharFromCode)                         \
   V(StringCompareAndBranch)                     \
-  V(StringLength)                               \
   V(SubI)                                       \
   V(TaggedToI)                                  \
   V(ThisFunction)                               \
@@ -2286,19 +2285,6 @@ 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) {