Using gcc as a build dependency only

[Bob Eager]

I have a port that, for reasons I won't go into, I build with gcc.

It all works fine with USE_GCC= yes - no problem.

The issue is that it's a build dependency and a run dependency. So
anyone wanting to use it has to install gcc, and is discouraged because
(a) it's big and (b) it drags in other stuff.

Presumably this is because it needs the gcc runtime, but I'm not sure.
And I can't see a runtime package that parallels the compiler.

Can anyone comment on this? And please don't say 'convert to clang'
because that isn't possible, at least not yet.