[DWARF][DebugInfo] Fix off-by-one error in size of DW_TAG_base_type types

Fix PR53163 by rounding the byte size of DW_TAG_base_type types up. Without
this fix we risk emitting types with a truncated size (including rounding
less-than-byte-sized types' sizes down to zero).

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D117124