Never mind, I found it.

Anyway, just one more question: if I want to use VS2017, should I put "<compatibility>vc141", or "<compatibility>vc14.1"?

This is what the file looks like right now (I changed the version from 1915 to 1916 and kept the last line from the default configuration file ("option.set keep-going : false ;").

From: Osman Zakir <osmanzakir90@hotmail.com>
Sent: Thursday, December 13, 2018 7:44 PM
To: boost-users@lists.boost.org
Subject: Re: [Boost-users] project-config.jam File for building Boost with LLVM toolchain?

I remember from a previous email thread that someone on this mailing list had given me a better configuration jamfile. I can't find it right now, so it'd be good if I could get that one again. It had a "using clang-win" line after the "import" command. And the <compatibility> tag, among some other things. I don't remember all of the commands, so I want to see it again.