MIPS: Accurate function prototypes for native calls from ARM simulator.

Port r14230 (76c22097)

Original commit message:
Native method invocation from the arm/simulator-arm.cc previously made
non-portable assumptions about calling conventions. This was okay for 32-bit
stack-based machines, where by-value structs are automatically materialized
on the stack, and where both int and double parameters could be passed on the
stack. However they are not okay for x86-64, which has an elaborate scheme
for passing parameters in registers.

This CL replaces the previous non-portable code paths with portable code,
using call-sites that accurately match the prototype of the callee.