remove prohibition of unmanaged constructed types

[RexJaeschke]

No description provided.

[BillWagner]

rebased on the latest draft v8 branch on 9/26/2023

[BillWagner]

This LGTM @RexJaeschke

I'm happy to merge at the next meeting.

[jskeet]

The title talks about unmanaged constructed types - the text seems to be about pointer types. (It looks like constructed types still count as managed.)
I think I need a bit more context to understand this change.

[BillWagner]

Added one possible suggestion.

[Nigel-Ecma]

One comment added in context as its in the range of the changes.

Lines 515, 617 & 699 probably also need to be changed. Also need to consider the unmanaged_type grammar (line 693), should it now allow a type parameter with the unmanaged constraint?

[jskeet]

(@jskeet to have another pass at this - in this PR.)

[jskeet]

And look for other places, e.g. 515.

[jskeet]

Also (try to) remove the grammar as type parameters can be unmanaged - instead, make references to it specify that the type must be unmanaged. (Do this in a separate commit.)

[jskeet]

We should talk about this again - I'm finding it hard to get my head back into it, so when we talk, let's make verbose notes.

[jskeet]

The latest merge has undone all the changes here... suggest we revert the last commit.

[BillWagner]

OK, I went through the merge, tried to revert and that failed to make any sensible changes (the only change left was the revert of the links for the "pointer" restriction.

Tried a rebase as well, and the same issue remained.

I've tried looking at a reflog and I can't find the actual changes there either.

[BillWagner]

Here's the original proposal as an issue in C# lang: dotnet/csharplang#1504

And the championed issue is here: dotnet/csharplang#1744

Finally, this issue contains some notes and details: dotnet/csharplang#1937