GBE: avoid one optimization pass to generate wide integer.

GBE: avoid one optimization pass to generate wide integer.

Integer type wider than 64 bit is hard to handle on Gen.
Let's try to prevent ScalarReplAggregates pass to generate
such type of integer.

v2:
fix compilation error with LLVM 3.3.

Signed-off-by: Zhigang Gong <zhigang.gong@intel.com>
Reviewed-by: "Yang, Rong R" <rong.r.yang@intel.com>