[pjmlp]

There is hardly any new C compiler that isn't C11.

[sarchertech]

I’ve been out of embedded for a bit but last I checked almost nothing actually implemented all of C11?

[pjmlp]

There is hardly any compiler worth using that isn't a fork of either GCC or clang.

So unless they are stuck on a pre-historic fork, they support C11 as much as clang and GCC do.

Exception for stuff like PIC, Z80,...

Which didn't even support proper C on their glory days.