Fix item-type in list to constant-array conversion with count()

[staabm]

before this PR we were loosing precision in this process as item-types were kind of generalized before.

I guess the original implementation was done before Type->getOffsetValueType() was a thing.

[phpstan-bot]

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[ondrejmirtes]

What about doing intersect with HasOffsetType instead of the for loop?

[staabm]

I tried using HasOffsetValueType but it still requires the loop

-                                               $valueTypesBuilder = ConstantArrayTypeBuilder::createEmpty();
+                                               $hasOffsetTypes = [];
                                                for ($i = 0; $i < $constantType->getValue(); $i++) {
-                                                       $offsetType = new ConstantIntegerType($i);
-                                                       $valueTypesBuilder->setOffsetValueType($offsetType, $argType->getOffsetValueType($offsetType));
+                                                       $hasOffsetTypes[] = new HasOffsetValueType(new ConstantIntegerType($i), $argType->getOffsetValueType(new ConstantIntegerType(
$i)));
                                                }
-                                               $valueTypes = $this->create($exprNode->getArgs()[0]->value, $valueTypesBuilder->getArray(), $context, false, $scope, $rootExpr);
+                                               $valueTypes = $this->create($exprNode->getArgs()[0]->value, TypeCombinator::intersect($argType, ...$hasOffsetTypes), $context, false,
 $scope, $rootExpr);

and it leads to less precise types, I think (at least less readable)

--- Expected
+++ Actual
@@ @@
-'array{ListCount\A, ListCount\A, ListCount\A}'
+'list<ListCount\A>&hasOffsetValue(0, ListCount\A)&hasOffsetValue(1, ListCount\A)&hasOffsetValue(2, ListCount\A)'

[staabm]

to drop the loop we could maybe use new HasOffsetValueType(IntegerRangeType::fromInterval(0, $constantType->getValue(), $offsetValueType) but this doesn't work because $offsetValueType is different per offset

[phpstan-bot]

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[ondrejmirtes]

Conflict :)

[phpstan-bot]

This pull request has been marked as ready for review.

[staabm]

Note to future me: Misses int-range support?

[staabm]

here we go: #3335

[ondrejmirtes]

Thank you!