Add new HSeqStringGetChar instruction.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index ed17be2b3de63c14c36a3710e825ce778a7b414c..717a07ab7a5ef0838771df76e1a80749d311cb2c 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -154,6 +154,7 @@ class LCodeGen;
   V(Random)                                     \
   V(RegExpLiteral)                              \
   V(Return)                                     \
+  V(SeqStringGetChar)                           \
   V(SeqStringSetChar)                           \
   V(ShiftI)                                     \
   V(SmiTag)                                     \
@@ -1281,6 +1282,21 @@ class LDateField V8_FINAL : public LTemplateInstruction<1, 1, 0> {
 };
 
 
+class LSeqStringGetChar V8_FINAL : public LTemplateInstruction<1, 2, 0> {
+ public:
+  LSeqStringGetChar(LOperand* string, LOperand* index) {
+    inputs_[0] = string;
+    inputs_[1] = index;
+  }
+
+  LOperand* string() const { return inputs_[0]; }
+  LOperand* index() const { return inputs_[1]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(SeqStringGetChar, "seq-string-get-char")
+  DECLARE_HYDROGEN_ACCESSOR(SeqStringGetChar)
+};
+
+
 class LSeqStringSetChar V8_FINAL : public LTemplateInstruction<1, 3, 0> {
  public:
   LSeqStringSetChar(LOperand* string,