[m-rev.] changed "no targets specified" message

[Zoltan Somogyi]

2022-11-22 17:15 GMT+11:00 "Peter Wang" <novalazy at gmail.com>:
> How about one of:
> 
> mercury_compile: *** Error: no target specified.
> mercury_compile: *** Error: no target or `MAIN_TARGET' specified.
> mercury_compile: *** Error: no target specified and `MAIN_TARGET' not defined.

I am fine with either the second or third, though I don't see the point
of quoting MAIN_TARGET.

> For other errors, I'd prefer each error message to appear on a single
> line, even if it might exceed what the compiler *thinks* the window
> width is. If they happen to be formatted with error_specs then I think
> they should behave as though --no-max-error-line-width was passed.

At the moment, there is no way to embed the instruction "ignore the
max line width" in an error_spec. Adding such a mechanism
would not be hard, but with the wordings above, it would not
be needed.

Zoltan.