Using tags in /say can crash all players on a server.

This issue can be replicated through a server console, or by using the command in a Minecraft 1.13-pre4 world that has a high amount of loaded entities, or a high amount of players.

Steps to Reproduce:

1. Log into any Minecraft world on version 1.13-pre4.
2. Use the command "/say @e" or "/say @a"
3. If there is a sufficient amount of players/entities, you will be kicked from the server with a message (attached).