… statics (#23188)

fixes #23186

As explained in #23186, generics can transform `genericProc[int]` into a
call `` `[]`(genericProc, int) `` which causes a problem when
`genericProc` is resemmed, since it is not a resolved generic proc. `[]`
needs unresolved generic procs since `mArrGet` also handles explicit
generic instantiations, so delay the resolved generic proc check to
`semFinishOperands` which is intentionally not called for `mArrGet`.

The root issue for
[t6137](https://github.com/nim-lang/Nim/blob/devel/tests/generics/t6137.nim)
is also fixed (because this change breaks it otherwise), the compiler
doesn't consider the possibility that an assigned generic param can be
an unresolved static value (note the line `if t.kind == tyStatic: s.ast
= t.n` below the change in sigmatch), now it properly errors that it
couldn't instantiate it as it would for a type param. ~~The change in
semtypinst is just for symmetry with the code above it which also gives
a `cannot instantiate` error, it may or may not be necessary/correct.~~
Now removed, I don't think it was correct.

Still possible that this has unintended consequences.

(cherry picked from commit e8092a5)

… statics (#23188)

fixes #23186

As explained in #23186, generics can transform `genericProc[int]` into a
call `` `[]`(genericProc, int) `` which causes a problem when
`genericProc` is resemmed, since it is not a resolved generic proc. `[]`
needs unresolved generic procs since `mArrGet` also handles explicit
generic instantiations, so delay the resolved generic proc check to
`semFinishOperands` which is intentionally not called for `mArrGet`.

The root issue for
[t6137](https://github.com/nim-lang/Nim/blob/devel/tests/generics/t6137.nim)
is also fixed (because this change breaks it otherwise), the compiler
doesn't consider the possibility that an assigned generic param can be
an unresolved static value (note the line `if t.kind == tyStatic: s.ast
= t.n` below the change in sigmatch), now it properly errors that it
couldn't instantiate it as it would for a type param. ~~The change in
semtypinst is just for symmetry with the code above it which also gives
a `cannot instantiate` error, it may or may not be necessary/correct.~~
Now removed, I don't think it was correct.

Still possible that this has unintended consequences.

(cherry picked from commit e8092a5)

fixes #23568, fixes #23310

In #23091 `semFinishOperands` was changed to not be called for `mArrGet`
and `mArrPut`, presumably in preparation for #23188 (not sure why it was
needed in #23091, maybe they got mixed together), since the compiler
handles these later and needs the first argument to not be completely
"typed" since brackets can serve as explicit generic instantiations in
which case the first argument would have to be an unresolved generic
proc (not accepted by `finishOperand`).

In this PR we just make it so `mArrGet` and `mArrPut` specifically skip
calling `finishOperand` on the first argument. This way the generic
arguments in the explicit instantiation get typed, but not the
unresolved generic proc.

fixes #23568, fixes #23310

In #23091 `semFinishOperands` was changed to not be called for `mArrGet`
and `mArrPut`, presumably in preparation for #23188 (not sure why it was
needed in #23091, maybe they got mixed together), since the compiler
handles these later and needs the first argument to not be completely
"typed" since brackets can serve as explicit generic instantiations in
which case the first argument would have to be an unresolved generic
proc (not accepted by `finishOperand`).

In this PR we just make it so `mArrGet` and `mArrPut` specifically skip
calling `finishOperand` on the first argument. This way the generic
arguments in the explicit instantiation get typed, but not the
unresolved generic proc.

(cherry picked from commit 09bd9d0)

…3731)

fixes #23730

Since #23188 the compiler errors when matching a type variable to an
uninstantiated static value. However sometimes an uninstantiated static
value is given even when only a type match is being performed to the
base type of the static type, in the given issue this case is:

```nim
proc foo[T: SomeInteger](x: T): int = int(x)
proc bar(x: static int): array[foo(x), int] = discard
discard bar(123)
```

To deal with this issue we only error when matching against a type
variable constrained to `static`.

Not sure if the `q.typ.kind == tyGenericParam and
q.typ.genericConstraint == tyStatic` check is necessary, the code above
for deciding whether the variable becomes `skConst` doesn't use it.

…3731)

fixes #23730

Since #23188 the compiler errors when matching a type variable to an
uninstantiated static value. However sometimes an uninstantiated static
value is given even when only a type match is being performed to the
base type of the static type, in the given issue this case is:

```nim
proc foo[T: SomeInteger](x: T): int = int(x)
proc bar(x: static int): array[foo(x), int] = discard
discard bar(123)
```

To deal with this issue we only error when matching against a type
variable constrained to `static`.

Not sure if the `q.typ.kind == tyGenericParam and
q.typ.genericConstraint == tyStatic` check is necessary, the code above
for deciding whether the variable becomes `skConst` doesn't use it.

(cherry picked from commit 128090c)