Fix PR33514

Summary:
The bug was uncovered after fix of  PR23384 (part 3 of 3).
The patch restricts pointer multiplication in SCEV computaion for ICmpZero.

Reviewers: qcolombet

Differential Revision: http://reviews.llvm.org/D36170

From: Evgeny Stupachenko <evstupac@gmail.com>
                         <evgeny.v.stupachenko@intel.com>
llvm-svn: 310092