rules alignment is to pick the alignment that corresponds to the smallest
specified alignment that is larger than the bit width of the type or the
largest specified integer alignment if none are larger than the bitwidth
of the type. For the byte size, the size returned is the next larger
multiple of the alignment for that type (using the above rule). This patch
also changes bit widths from "short" to "uint32_t" to ensure there are
enough bits to specify any bit width that LLVM can handle (currently 2^23);
16-bits isn't enough.

llvm-svn: 34431