Tentative implementation of string slices (hidden under the flag --string-slices).

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 70c348de69f8c406b8fada3988e1f9958275fbb5..cca5fc84ac1c12e2e31396870e6d81e79dffc726 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -1695,11 +1695,12 @@ class LStringAdd: public LTemplateInstruction<1, 2, 0> {
 
 
 
-class LStringCharCodeAt: public LTemplateInstruction<1, 2, 0> {
+class LStringCharCodeAt: public LTemplateInstruction<1, 2, 1> {
  public:
-  LStringCharCodeAt(LOperand* string, LOperand* index) {
+  LStringCharCodeAt(LOperand* string, LOperand* index, LOperand* temp) {
     inputs_[0] = string;
     inputs_[1] = index;
+    temps_[0] = temp;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(StringCharCodeAt, "string-char-code-at")