Remove unused code, AstValueFactory::ConcatStrings.

src/ast/ast-value-factory.cc

Index: src/ast/ast-value-factory.cc
diff --git a/src/ast/ast-value-factory.cc b/src/ast/ast-value-factory.cc
index ed2976f52a98b15ef6872e9363bd272c6dd7e9e9..42295ab6a528a3d6ef20ce25ee3f5bf8fc2a4276 100644
--- a/src/ast/ast-value-factory.cc
+++ b/src/ast/ast-value-factory.cc
@@ -260,39 +260,6 @@ const AstConsString* AstValueFactory::NewConsString(
   return new_string;
 }
 
-const AstRawString* AstValueFactory::ConcatStrings(const AstRawString* left,
-                                                   const AstRawString* right) {
-  int left_length = left->length();
-  int right_length = right->length();
-  const unsigned char* left_data = left->raw_data();
-  const unsigned char* right_data = right->raw_data();
-  if (left->is_one_byte() && right->is_one_byte()) {
-    uint8_t* buffer = zone_->NewArray<uint8_t>(left_length + right_length);
-    memcpy(buffer, left_data, left_length);
-    memcpy(buffer + left_length, right_data, right_length);
-    Vector<const uint8_t> literal(buffer, left_length + right_length);
-    return GetOneByteStringInternal(literal);
-  } else {
-    uint16_t* buffer = zone_->NewArray<uint16_t>(left_length + right_length);
-    if (left->is_one_byte()) {
-      for (int i = 0; i < left_length; ++i) {
-        buffer[i] = left_data[i];
-      }
-    } else {
-      memcpy(buffer, left_data, 2 * left_length);
-    }
-    if (right->is_one_byte()) {
-      for (int i = 0; i < right_length; ++i) {
-        buffer[i + left_length] = right_data[i];
-      }
-    } else {
-      memcpy(buffer + left_length, right_data, 2 * right_length);
-    }
-    Vector<const uint16_t> literal(buffer, left_length + right_length);
-    return GetTwoByteStringInternal(literal);
-  }
-}
-
 void AstValueFactory::Internalize(Isolate* isolate) {
   // Strings need to be internalized before values, because values refer to
   // strings.