Converting RecordLayout fields to CharUnits

The RecordLayout class has several fields that are stored in bit units
but appear (at least on X86 Linux) to always hold values that are
multiples of char size. Specifically:
  - Size
  - DataSize
  - Alignment
  - CXXRecordLayoutInfo::NonVirtualSize
  - CXXRecordLayoutInfo::NonVirtualAlign

Am I right in assuming that these values are always multiples of the
char size? If so, is there any reason why they shouldn't be converted
to CharUnits?

-Ken

I take from that lack of responses that there are not any strong
objections to proceeding with a conversion to CharUnits. The first of
the changes is committed as 124646.

-Ken