Added the ability to see block variables when looking up addresses

with the "target modules lookup --address <addr>" command. The variable
ID's, names, types, location for the address, and declaration is
displayed.

This can really help with crash logs since we get, on MacOSX at least,
the registers for the thread that crashed so it is often possible to
figure out some of the variable contents. 

llvm-svn: 134886