Fasta: Implement adjusted member conflict rules

[eernstg]

This is the Fasta specific issue for #33235, which has the details.

[kmillikin]

This is basically a duplicate of #32613 and #32014; related to #31596, #32917, and #30674.

[eernstg]

@kmillikin, those issues were created long before dartLangSpec.tex was updated as described in #33235, so they can hardly require the same changes; this means that I'd need to look into all those issues to make sure that they request the right thing. Thanks for the info!

[eernstg]

PS: Please postpone the implementation requested in this issue for a few days—one more update to the language specification is currently under review (marked in #33235 as 'Update under review', handled here). We will add yet another comment here when that update has been resolved.

(Edit: done, see below)

[eernstg]

@kmillikin, regarding issues #30674, #31596, #32014, and #32917: I took a look at them and concluded that they are about overriding (which is concerned with two declarations of a member of the same kind). This means that there is no overlap with this issue (which is concerned with situations involving two different kinds of members, e.g., a getter and a setter, or a static member and an instance member).

In #32613 I added a reference to a table in #33235, which may be helpful because it lists all cases.

[eernstg]

As of 08c893d, the updated and simplified rules in the specification have been landed, so the work here may proceed.

[kmillikin]

We are currently missing the ones involving static members and a few of the other ones:

• declares constructor C.n and declares static setter n=
• declares static getter n and has instance getter n
• declares static getter n and has instance method n
• declares static getter n and has instance setter n=
• declares static method n and has instance getter n
• declares static method n and has instance method n
• declares static method n and has instance setter n=
• declares static setter n= and declares static method n
• declares static setter n= and has instance getter n
• declares static setter n= and has instance method n
• declares static setter n= and has instance setter n=
• has instance setter n= and has instance method n (we catch this one if one or both methods are inherited, but not if they're both declared in the class)

[kmillikin]

@askeksa-google can you take "constructor/static setter" and "static setter/static method"?

I'll implement the others as part of override checking during top-level type inference.

[johnniwinther]

co19_2/Language/Classes/Constructors/name_t01 and others are still missing a compile-time error.

[askeksa-google]

co19_2/Language/Classes/Constructors/name_t01 is incorrect, as the code in it is valid Dart. A named constructor does not conflict with an instance variable. This and similarly incorrect tests are marked in co19_2-kernel.status as Legal, see #33235.

[askeksa-google]

I have filed dart-lang/co19#179 for these incorrect tests.