Very interesting. You can write a C program that when compiled, indicates whether the compiler allows nesting or not.
20180709/DuckDuckGo c nested comment
20180709/https://stackoverflow.com/questions/6698039/nested-comments-in-c-c#6698115
Well, I guess nested comments is a distinct artifact of the Borland C/C++ compilers. Most other mainstream compilers appear not to support it, but were explicitly rigged up so that they issue an error message should someone run through some Borland C/C++ code that contains nested comments.
This is a funny StackOverflow answer, in light of this knowledge.
20180709/https://stackoverflow.com/questions/2969198/why-are-nested-comments-forbidden
20180709/DuckDuckGo borland c nested comments
20180709/http://edn.embarcadero.com/article/20997