Account for CPE alignment when searching for new water.

Account for CPE alignment when searching for new water.

Constant pool entries with different alignment may cause more alignment
padding to be inserted. Compute the amount of padding needed, and try to
pick the location that requires the least amount of padding.

Also take the extra padding into account when the water is above the
use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146458 91177308-0d34-0410-b5e6-96231b3b80d8