[builtins] String.prototype.slice as a CSA builtin.

src/builtins/builtins-definitions.h

Index: src/builtins/builtins-definitions.h
diff --git a/src/builtins/builtins-definitions.h b/src/builtins/builtins-definitions.h
index b9b50b7dea9603d8157757f974f8234aff4fe4a9..dcb753236f74c3c52e8e690aaeed0f0346c1e4dc 100644
--- a/src/builtins/builtins-definitions.h
+++ b/src/builtins/builtins-definitions.h
@@ -854,6 +854,8 @@ namespace internal {
   CPP(StringPrototypeLocaleCompare)                                            \
   /* ES6 #sec-string.prototype.replace */                                      \
   TFJ(StringPrototypeReplace, 2, kSearch, kReplace)                            \
+  /* ES6 #sec-string.prototype.slice */                                        \
+  TFJ(StringPrototypeSlice, 2, kStart, kEnd)                                   \
   /* ES6 #sec-string.prototype.split */                                        \
   TFJ(StringPrototypeSplit, 2, kSeparator, kLimit)                             \
   /* ES6 #sec-string.prototype.substr */                                       \