000314.1 B A R. Brender Representation Dwarf vs Location expressions

The purpose of this proposal is to disentangle the concepts of Dwarf
stack machines from location expressions, to make it clearer that location
expressions (and lists) use "Dwarf expressions" but Dwarf expressions
can also be used for other purposes as well (eg, to compute values).

This is a sketch of the editorial changes that are proposed. If this
proposal is approved, then a detailed editorial revision will be prepared
for review/approval.

1) Split the existing Section 2.4 into two sections:

        2.4 Dwarf Expressions
        2.5 Location Expressions

    and renumber the following sections appropriately.

2) The first part of 2.4 (up to but not including 2.4.1) will be revised
   to introduce Dwarf Expressions generally

3) The existing material in 2.4.2 thru 2.4.5 (pp10-17) will be retained
   in the new 2.4 (and renumbered 2.4.1 thru 2.4.4), but the term location
   expression will be changed to Dwarf expression.

4) The existing material in 2.4.1 and 2.4.6 will be reworked to become

        2.5.1 Location Expressions
        2.5.2 Location Lists

   in the new Section 2.5. The main editorial change is to be clear
   that location expressions are represented using Dwarf expressions,
   as defined in the new Section 2.4.

5) The remainder of the document also needs to be audited to determine
   whether or not other existing uses of the term location expression
   should be changed to Dwarf expression.

6) New attributes that use the stack machine mechanism to produce values
   will be defined in terms of "Dwarf expressions" (for example,
   DW_AT_allocated and others).