This program popped up on Hacker News recently. It's the only modern compiler I've ever seen that doesn't have dependencies and is easily modified. So I added all of the missing GNU extensions I like to use which means it might be possible soon to build on non-Linux and have third party not vendor gcc binaries.
Sourced from Chromium due to overextended influence by maintainers whose important contributions in this field should be recognized by clarifying claims of ownership for posterity. See also libc/str/undeflate.c