Correctly allign arrays on 32 bit systems.

Before this patch we would align

long long int big[1024];

to 4 bytes on 32 bit systems. The problem is that we were only looking
at the element type when getLargeArrayMinWidth returned non zero.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@187897 91177308-0d34-0410-b5e6-96231b3b80d8