dwarf2cfi: Simplify re-initialization for each function.

dwarf2cfi: Simplify re-initialization for each function.

There's no point calling lookup_cfa to re-create the CFA
we initialized just a few lines above.

        * dwarf2cfi.c (lookup_cfa): Remove.
        (execute_dwarf2_frame): Assert queues are empty on entry.
        Setup initial cfa directly, not via lookup_cfa.
        Don't clear args_size state here.

From-SVN: r176098