Miscellaneous changes for HM type inference and QEP 2

[bamarsha]

• Add parsing for empty array literals.
• Support sized array literals in attribute arguments.
• Replace warning when a type parameter doesn't occur in the argument with a warning when the type parameter is unused (in both the argument and the return types).
• Add tests for integral, iterable, numeric, semigroup, and unwrap constraints.

[bettinaheim]

• I am looking for an override of OnSizedArray in the QIR emission and don't see it yet. What's the plan for that?
• Also, in CompilerDataStructures.cs, I see a couple of QsExpressionKindNewArray without a matching QsExpressionKindSizedArray - is there something missing there? In BondSchemaTranslator.cs, e.g. in QsExpressionKindComposition NewArray is listed but not SizedArray. I would also expect "SizedArray" to occur in CompilerObjectTranslator. @cesarzc Could you take a look at the bond schemas to have a second set of eyes on that?
• In ConstantPropagation.fs in shouldPropagate there is NewArray listed but not SizedArray, same in Evaluation.fs, same in HelperFunctions.fs in isLiteral
• In NamespaceManager.fs in ExpressionHash I would also expect to find SizedArray
• There is also an overload missing in QsharpCodeOutput.cs

Also, is there a matching PR on the runtime repo to add support in the C# generation?
Edit: I reviewed (i.e. set changes requested) in the same way as I would for a PR to main - since this is going into a feature branch, I am happy to remove the blocker to split it into several PRs if you prefer. If you want to do that, then I suggest to make a task list in a GitHub issue to make sure the remaining work is tracked and not forgotten.

[bamarsha]

• I am looking for an override of OnSizedArray in the QIR emission and don't see it yet. What's the plan for that?
• Also, in CompilerDataStructures.cs, I see a couple of QsExpressionKindNewArray without a matching QsExpressionKindSizedArray - is there something missing there? In BondSchemaTranslator.cs, e.g. in QsExpressionKindComposition NewArray is listed but not SizedArray. I would also expect "SizedArray" to occur in CompilerObjectTranslator. @cesarzc Could you take a look at the bond schemas to have a second set of eyes on that?
• In ConstantPropagation.fs in shouldPropagate there is NewArray listed but not SizedArray, same in Evaluation.fs, same in HelperFunctions.fs in isLiteral
• In NamespaceManager.fs in ExpressionHash I would also expect to find SizedArray
• There is also an overload missing in QsharpCodeOutput.cs

Also, is there a matching PR on the runtime repo to add support in the C# generation?

I don't think any of these issues are new in this PR. The SizedArray expression kind was added in #856, with corresponding C# generation added in microsoft/qsharp-runtime#507.

[bettinaheim]

• I am looking for an override of OnSizedArray in the QIR emission and don't see it yet. What's the plan for that?
• Also, in CompilerDataStructures.cs, I see a couple of QsExpressionKindNewArray without a matching QsExpressionKindSizedArray - is there something missing there? In BondSchemaTranslator.cs, e.g. in QsExpressionKindComposition NewArray is listed but not SizedArray. I would also expect "SizedArray" to occur in CompilerObjectTranslator. @cesarzc Could you take a look at the bond schemas to have a second set of eyes on that?
• In ConstantPropagation.fs in shouldPropagate there is NewArray listed but not SizedArray, same in Evaluation.fs, same in HelperFunctions.fs in isLiteral
• In NamespaceManager.fs in ExpressionHash I would also expect to find SizedArray
• There is also an overload missing in QsharpCodeOutput.cs

Also, is there a matching PR on the runtime repo to add support in the C# generation?

I don't think any of these issues are new in this PR. The SizedArray expression kind was added in #856, with corresponding C# generation added in microsoft/qsharp-runtime#507.

See the edit above (you have beaten me to it with your reply):
Edit: I reviewed (i.e. set changes requested) in the same way as I would for a PR to main - since this is going into a feature branch, I am happy to remove the blocker to split it into several PRs if you prefer. If you want to do that, then I suggest to make a task list in a GitHub issue to make sure the remaining work is tracked and not forgotten.

I am listing the things that are missing for the feature to be complete, since this PR is titled "Final touches for ... QEP 2"; up to you when to address them as long as they are done before the merge to main. Could you please track the items I listed somewhere, if they are not addressed with this PR?

[bamarsha]

Sorry, the name is misleading. I didn't intend for this to be the final PR.

[bamarsha]

Also, in CompilerDataStructures.cs, I see a couple of QsExpressionKindNewArray without a matching QsExpressionKindSizedArray - is there something missing there?

That's intentional. SizedArray uses QsExpressionKindExpressionDouble.

In BondSchemaTranslator.cs, e.g. in QsExpressionKindComposition NewArray is listed but not SizedArray. I would also expect "SizedArray" to occur in CompilerObjectTranslator.

Also intentional, due to piggy-backing on the existing QsExpressionKindExpressionDouble.

@cesarzc Could you take a look at the bond schemas to have a second set of eyes on that?

@cesarzc already reviewed the changes to the Bond schema in #856.

[bamarsha]

I am looking for an override of OnSizedArray in the QIR emission and don't see it yet. What's the plan for that?

Keep in mind that SizedArray was added before QIR generation was even in main. :) It should be added before merging the feature branch, though, yes.

Remaining work is tracked in #857