Which parts of Lua C-code handle string literals and multi-line comments?

[Claudio Grondi <claudio.grondi@...>]

Lua provides support for multi-line string literals invoked by `[[` and 
finalized with `]]` and for multi-line comments invoked with `--[[`, 
`--[=[`, ...

I have searched Lua C-code for `--[[`, `--[=` and `[[` but failed to 
find this patterns which I would like to replace for custom purposes 
with another ones.

Any hints towards where to look and what to change?