All targets (at least on sanitizer builds) unconditionally depend
on //build/config/sanitizers:deps.

It is necessary for bug 593874 that all targets now also depend
on //buildtools/third_party/libc++:libcxx_proxy.  This requires
adding a new "global dependency": //build/config:exe_and_shlib_deps.

This CL updates references to sanitizers:deps to instead refer to
//build/config:exe_and_shlib_deps.

BUG=chromium:723069
R=bradnelson@chromium.org

Review-Url: https://codereview.chromium.org/2894013003
Cr-Commit-Position: refs/heads/master@{#45435}