ByteBuffer: Add slice_view(). Works like slice() but makes a wrapper …

…only.

So we already have ByteBuffer::wrap() which is like a StringView for random
data. This might not be the best abstraction actually, but this will be
immediately useful so let's add it.

AK/ByteBuffer.h

@@ -155,6 +155,17 @@ class ByteBuffer {
  m_impl->trim(size);
  }
 
+ ByteBuffer slice_view(int offset, int size) const
+ {
+ if (is_null())
+ return {};
+ if (offset >= this->size())
+ return {};
+ if (offset + size >= this->size())
+ size = this->size() - offset;
+ return wrap(offset_pointer(offset), size);
+ }
+
  ByteBuffer slice(int offset, int size) const
  {
  if (is_null())