https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101246
--- Comment #6 from Lance Fredrickson <lancethepants at gmail dot com> --- So I compared runtime.inc in gcc 10.3 and gcc 11.1, and they have quite a bit different. I tried using the runtime.inc file from 10.3 in 11.1, and it does allow it to finish compiling, and I appear to be able to compile a simple go program. I also just removing struct _FILE, which has those to fields __lock and __state and also completes and I appear to be able to compile some simple go programs. Not sure if any of this is helpful. I've been trying to figure out all the file generation is happening, but it's a lot to take in.
