[m-rev.] for post-commit review: don't expand insts in other insts' names

[Julien Fischer]

On Sun, 6 Feb 2022, Zoltan Somogyi wrote:

> Don't expand insts in inst names.
> 
> compiler/error_msg_inst.m:
>     When the first occurrence of a named inst I2 is an argument of another
>     named inst I1, do *not* expand I2 there. Instead, expand it one of its
>     occurrences in the *expansion* of I1.
>
>     To expand I2 at its *first* occurrence in the expansion of I1,
>     change the way to format lists of insts to format the head inst
>     before formatting the tail insts.
>
>     Shorten a field name.
> 
> tests/invalid/html.err_exp:
>     Expect the fix for the "omitted insts" bug above.

That looks fine.

Julien.