Infineon tricore compiler from hightec. Compilers are actually, IMO, one of the things that are the most easy to have GPL because you can use it internally however you want without releasing the source outside. You could build whatever you want and you don't have to ship it on the final HW. A kernel does not afford you such a thing, you MUST ship it with your product.
Thanks for the example! Your opinion here aligns with mine: GCC's GPL status has manifestly not been an issue for vendors in the past. I think the reason for vendors selecting LLVM has much more to do with the fact that LLVM is easier to develop on than GCC.