This makes the implementations of MacroAssembler::InvokeBuiltin go
through the InvokeFunctionCode helper on all architectures. This helper
knows how to correctly set up all registers (i.e. argument count and the
new target value).

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1488303008

Cr-Commit-Position: refs/heads/master@{#32646}