Fix type annotations in linkers for python < 3.5.4
Fix type annotations in linkers for python < 3.5.4

Before python 3.5.4 typing didn't have the NoReturn type, use a string
to forward declare it.

aside: I can't wait to be able to use python 3.7's
__future__.annotations and not have to deal wit hthis anymore.

Fixes #5822

becm/meson,QuLogic/meson,pexip/meson,becm/meson,becm/meson,mesonbuild/meson,jpakkane/meson,becm/meson,jpakkane/meson,mesonbuild/meson,becm/meson,QuLogic/meson,becm/meson,QuLogic/meson,pexip/meson,pexip/meson,jpakkane/meson,mesonbuild/meson,QuLogic/meson,QuLogic/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,becm/meson,mesonbuild/meson,jpakkane/meson,QuLogic/meson,becm/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,QuLogic/meson,pexip/meson,pexip/meson,jpakkane/meson,becm/meson,jpakkane/meson,pexip/meson,QuLogic/meson,jpakkane/meson,QuLogic/meson,pexip/meson,jpakkane/meson,becm/meson,jpakkane/meson,pexip/meson,mesonbuild/meson