- zext the value to alloc size first, then check if the value repeats
with zero padding included. If so we can still emit a .space
- Do the checking with APInt.isSplat(8), which handles non-pow2 types
- Also handle large constants (bit width > 64)
- In a ConstantArray all elements have the same type, so it's sufficient
to check the first constant recursively and then just compare if all
following constants are the same by pointer compare
llvm-svn: 239977
Benjamin Kramer