Make mem{cpy,move,set} pnacl bitcode disablement apply to biased bitcode.

This is to avoid miscompilations where the bitcode functions are
specialized to an incomplete set of the callers (more callers
introduced very late by codegen).

Previously this only applied to __pnacl__ and not biased bitcode.
Use a separate preprocessor define to disable.

Must update DEPS along with:  https://codereview.chromium.org/844473003/

Fixes the callingconv test failure in:
BUG= https://code.google.com/p/nativeclient/issues/detail?id=4026
R=dschuff@chromium.org

Review URL: https://codereview.chromium.org/855013002
3 files changed