Make clang generate the unwind tables correctly for exception support.

Without this, clang doesn't generate a personality routine entry for
exception hanler table entries that require something beyond what is
doable with basic unwind codes.  Instead it inserts an 0x00000001 for
the eit data causing exception propagation to fail.

Change-Id: I24b511dd222a9898b5a319dd36e93405742ca8ef
Make lsda a direct function parameter and add TODOs

Change-Id: I69db3beefca20a53c84630875e3c5c9729b0b9ff