compilers/d: fix mangling of rpath-link in DMD-like compilers
compilers/d: fix mangling of rpath-link in DMD-like compilers

We didn't consider that it has arguments following it, so the resulting
compiler command line ended up with stuff like:

-L=-rpath-link -L=-L=/path/to/directory -L=more-args

and the directory for rpath-link got eaten up as a regular -L path to
the compiler rather than being passed as -Xlinker to the linker.

Then the -rpath-link would consume the next -Xlinker argument, end up
with the wrong rpath-link (may or may not cause link errors) and then
disappear arguments we need.

As an example failure mode, if the next argument is -soname this treats
the soname text as an input file, which probably does not exist if it
was generated in a subdirectory, and also because it can never be
successfully built in the first place -- though if it did, it would link
to itself which is very wrong.

pexip/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,pexip/meson,pexip/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,pexip/meson