Add support for dump and listing files

[nberth]

Closes #328 & #348

[GitMensch]

Does this include the use of the LSP on those (outline based on this file only)? Otherwise this may only be a partial solve of the referenced issue.

[nberth]

Does this include the use of the LSP on those (outline based on this file only)? Otherwise this may only be a partial solve of the referenced issue.

Not yet, this is only preliminary support; I'll add a separate issue for the outline.

[nberth]

Does this include the use of the LSP on those (outline based on this file only)? Otherwise this may only be a partial solve of the referenced issue.

Not yet, this is only preliminary support; I'll add a separate issue for the outline.

Actually that was much more easy to do than I anticipated ;-)

[nberth]

@GitMensch Note: this currently hardcodes the format for listing and dump files to an equivalent of -fformat=VARIABLE. If such files may include lines longer than 250 chars, then maybe we'd need another source-format similar to FIXED with with no right margin.

[GitMensch]

Nice. I'll check once the CI vsix exists, or when there is another binary available.

[GitMensch]

Things to check: wide and normal listing -T and -t along with/without symbols and -Xref.