src: remove CopyBuffer

CopyBuffer was used by the PBKDF2 implementation prior to the big
refactor, which removed those call sites.

PR-URL: nodejs#43463
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>

src/crypto/crypto_util.h

@@ -777,20 +777,6 @@ class ArrayBufferOrViewContents {
   std::shared_ptr<v8::BackingStore> store_;
 };
 
-template <typename T>
-std::vector<T> CopyBuffer(const ArrayBufferOrViewContents<T>& buf) {
-  std::vector<T> vec;
-  vec->resize(buf.size());
-  if (vec->size() > 0 && buf.data() != nullptr)
-    memcpy(vec->data(), buf.data(), vec->size());
-  return vec;
-}
-
-template <typename T>
-std::vector<T> CopyBuffer(v8::Local<v8::Value> buf) {
-  return CopyBuffer(ArrayBufferOrViewContents<T>(buf));
-}
-
 v8::MaybeLocal<v8::Value> EncodeBignum(
     Environment* env,
     const BIGNUM* bn,