get_mem_attrs documentation

[Mark Mitchell]

Kenner --

The documentation for get_mem_attrs is lacking explanations of the
following arguments: alias, expr, offset, size, and align.

Our coding standards require explicit documentation for each argument.
Please add this information.  Please also indicate whether align is
scaled in bits, bytes, and whether it is a power-of-two
representation; that's often confusing.

Thanks,

--
Mark Mitchell                   mark@codesourcery.com
CodeSourcery, LLC               http://www.codesourcery.com