Use before-scope for evaluating array_splice argument types

[phpstan-bot]

Same than #5579 for array_splice.

Fixes phpstan/phpstan#13510

[VincentLanglet]

Would it work if we keep trace of

$scopeBeforeArgs = $scope;

before the

$argsResult = $nodeScopeResolver->processArgs($stmt, $functionReflection, null, $parametersAcceptor, $normalizedExpr, $scope, $storage, $nodeCallbackForArgs, $context);

call line 268 ?

[phpstan-bot]

Done. I implemented the reviewer's suggestion: instead of per-argument $storage->findBeforeScope() lookups, we now save $scopeBeforeArgs = $scope once before processArgs and use that single scope for all argument type evaluations in both the array_push/array_unshift and array_splice handlers. This is simpler (net -5 lines) and semantically equivalent — the scope before args correctly reflects the types at evaluation time for all value arguments. All tests pass and make phpstan reports no errors.

[VincentLanglet]

Why not just

new NativeTypeExpr(
					$this->getArrayFunctionAppendingType($functionReflection, $scopeBeforeArgs, $normalizedExpr),
					$this->getArrayFunctionAppendingType($functionReflection, $scopeBeforeArgs->doNotTreatPhpDocTypesAsCertain(), $normalizedExpr),

[phpstan-bot]

Done. I implemented the reviewer's suggestion: instead of pre-computing argument types from $scopeBeforeArgs and passing them via a $precomputedArgTypes array, we now pass $scopeBeforeArgs directly as the scope to getArrayFunctionAppendingType. This is simpler (net -12 lines) because the function already uses $scope->getType() internally for both the array type and argument types — passing the before-args scope gives correct results for both. All tests pass and make phpstan reports no errors.

[staabm]

do we need the same fix for more functions in this handler?
(separate PR)

[VincentLanglet]

do we need the same fix for more functions in this handler? (separate PR)

When I ran the bot, it only opened the PR "Use before-scope for evaluating array_push/array_unshift/array_splice argument types" ; so I'm not sure there is more