Add link GN rules to non-win build, set c++14 in CC flags.
Add link GN rules to non-win build, set c++14 in CC flags.

Very minimal, I'm not sure if these actually work yet, but gets things
compiling farther on Fuchsia.

Bug: crashpad:79
Change-Id: I9c1ac7f2b13d0580d860334746d23cc6ab7e04ec
Reviewed-on: https://chromium-review.googlesource.com/783811
Reviewed-by: Robert Sesek <f55ad94e336f3a28322d0a25d280221ea9daf7a3@chromium.org>

chromium/mini_chromium,chromium/mini_chromium,chromium/mini_chromium