Fix signature of __nacl_irt_xx functions

These functions should use nacl_abi types rather than
their glibc equivalents.

TEST=nacl-toolchain-precise64-glibc bot
BUG= https://code.google.com/p/nativeclient/issues/detail?id=4252
R=mcgrathr@chromium.org

Review URL: https://codereview.chromium.org/1261203002 .
4 files changed