The natural comparisons are libraries like glibc and newlib, which do support lots of architectures and more importantly make porting to new architectures or taking advantage of platform features pretty straightforward.
for embedded defs not against portable alternatives like this tho.
however ops post sure gets off on the wrong foot by saying this is "fixing C". the hubris of mankind on full display, yet again
Aside from various different variations of ARM, I’ve worked several variations of x86 and AMD64, SPARC, PowerPC, MIPS and others I’ve likely forgotten. Not to mention a few 8-bit CPUs too, but those there more than 20 years ago and not really fair to discuss here.