move gmi set function decls inside extern C
move gmi set function decls inside extern C

yangf4/core,yangf4/core,YetAnotherMinion/core,YetAnotherMinion/core,yangf4/core,yangf4/core,YetAnotherMinion/core,YetAnotherMinion/core,yangf4/core,YetAnotherMinion/core