ptc: pascal to C

Not the same as p2c or ptoc:

https://www.google.com/search?q=%22Per+Bergsten%22+%22pascal+to+c%22

I don't know where the definitive source is - my own copy is at https://gtoal.com/src/ptc/ ...

This is the one that used to be used to build the TeX suite.

Graham

Review the repository's compiler list and compare the ptc references in the issue, including the search result and the copy at https://gtoal.com/src/ptc/. Confirm that this is the Pascal-to-C compiler formerly used to build the TeX suite, then add a concise entry with the available source reference; done means the list identifies ptc without confusing it with p2c or ptoc.

Written by the indexing model from the issue text.