[gcc] Make nacl calls CALLs.

Change nacl calls from UNSPEC (fnaddr) to CALL (MEM (UNSPEC (fnaddr))).

In places where gcc processes CALLs, we copy-pasted the code for nacl calls implemented via UNSPEC_NACLCALL. Now we remove these changes.

Review URL: http://codereview.chromium.org/2852035
5 files changed