Tested versions

4.5.1 and current master

System information

Linux

Issue description

When opening a very large, one line JSON file (197KB), the godot editor just freezes (also across restarts).

When profiling it hangs in the following stacktrace:

It uses >90% of time in this function:

I therefor assume it's necessary to add some functionality, that disables the syntax highlighter for files with more than 20k characters or something like that.

Steps to reproduce

1. Create a big json file, one line.
2. open it in godot text editor

Minimal reproduction project (MRP)