Clarify use of DWARF versions

[Stammark]

Hi all,

In:

https://github.com/ARM-software/abi-aa/blob/main/aadwarf32/aadwarf32.rst#overview
https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst#overview

We have references to DWARF 3.0:
The ABI for the Arm architecture specifies the use of DWARF 3.0-format debugging data.
The ABI for the Arm 64-bit architecture specifies the use of DWARF 3.0 format debugging data.

These could be misread as a "Arm requires you to use DWARF 3.0" which isn't valid in practice, these days.

I'm raising this issue to suggest that be changed to more flexible wording. That could be something like:

• We recommend/require? a minimum of DWARF 3.0. Then the rest of the doc is version-agnostic (>= 3.0 is implied)
• We recommend/require? a minimum of DWARF 2.0. Then the rest of the doc is version-agnostic (>= 2.0 is implied)
• We make the whole doc version-agnostic (unlikely to be possible, as that would include DWARF1)

And in all those cases we could come up with a statement like "refer to the documentation of your debugger for the best compatible DWARF version" (since that is outside the scope of the aadwarf doc)