I was curious if it's possible to build Linux kernel without GNU toolchain (gcc+autotools).
I found out that it is possible: after applying patches from llvm.linuxfoundation.org, it was possible to build Linux kernel with clang. GNU linker was used.
The alternative to
gold which is also part of GNU binutils. Popular musl+clang toolchain ELLCC also uses GNU binutils.
There are more alternatives:
lld (no stable releases),
mclinker (no stable releases).
Does alternative to GNU binutils exist? Probably, building on Mac OS X or FreeBSD doesn't involve GNU tools.