linkers: Add a PosixDynamicLinkerMixin
linkers: Add a PosixDynamicLinkerMixin

This is a mixin class for DynamicLinkers that aims to provide only the
most basic posix-like linker arguments, in other words bits that gnu ld,
apple's ld, solaris's ld, and other completely disjoint linkers that are
used on Unix-like OSes share.

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