llvm: simplify getFunctionCalls/Exits

We have also const_inst_iterator, so no need for const_cast. Remove
that crap.
slic: fss, nicer dumping

Add a space after offset.
slic: remove StaticSlicer.h

We do not need that header, leave it all in one file, so that we know
what is going on. And make thus some functions static.
slic: ss, fix bug in relevants

In emitToExits, we passed a non-const relBgn to getRelevantVarsAtExit
which moves with that. And we never reset the iterator. This is a bug
introduced by:
	commit d53de24fa53d3ccb6910c9744a80af80e49e656d
	Author: Jiri Slaby <jirislaby@gmail.com>
	Date:   Thu Jul 18 09:53:13 2013 +0200

	    slic: remove relevants template

Make it const again and pass it as a value, so that a copy is made
automatically. The same for emitToCalls+getRelevantVarsAtCall.
slic: ss, cleanup

Whitespace cleanup and refactoring.
slic: do not define Pointee

It is defined in the points-to analysis. So remove the duplicit
definition.
mods: little cleanup

Move computeModifies into rhe llvm::mods block so we do not need to
prepend it.
mods: teach it to use Pointee

As we have to distinguish -1 and 0 for alloca...
slic: fss, fix ExtraRefs and LoadInst

LoadInst from ExtraReferenced variables actually referecens also
(variable, 0) apart from (variable, -1).