Simplify by-ref constant array handling via MutatingScope::enterForeach

Remove the isConstantArray()->no() guard from the with-key
IntertwinedVariableByReferenceWithExpr setup in enterForeach.
The ArrayDimFetch-based intertwined expression correctly targets
individual elements via the key variable, so it works for constant
arrays (unlike the SetExistingOffsetValueTypeExpr path which
updates all values at once and must remain guarded).

This lets the intertwined mechanism automatically propagate by-ref
type changes to the dim fetch for constant arrays, removing the
need for the elseif ($stmt->byRef) fallback branches in the
post-loop rewrite in NodeScopeResolver.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

src/Analyser/MutatingScope.php

@@ -2373,7 +2373,7 @@ public function enterForeach(self $originalScope, Expr $iteratee, string $valueN
 		if ($keyName !== null) {
 			$scope = $scope->enterForeachKey($originalScope, $iteratee, $keyName);
 
-			if ($valueByRef && $iterateeType->isArray()->yes() && $iterateeType->isConstantArray()->no()) {
+			if ($valueByRef && $iterateeType->isArray()->yes()) {
 				$scope = $scope->assignExpression(
 					new IntertwinedVariableByReferenceWithExpr($valueName, new Expr\ArrayDimFetch($iteratee, new Variable($keyName)), new Variable($valueName)),
 					$valueType,

src/Analyser/NodeScopeResolver.php

@@ -1377,8 +1377,6 @@ public function processStmtNode(
 							if ($dimFetchType->isSuperTypeOf($valueVarType)->yes()) {
 								$dimFetchType = $valueVarType;
 							}
-						} elseif ($stmt->byRef && $originalValueExpr !== null) {
-							$dimFetchType = $scopeWithIterableValueType->getType($stmt->valueVar);
 						}
 						$arrayDimFetchLoopTypes[] = $dimFetchType;
 						$keyLoopTypes[] = $scopeWithIterableValueType->getType($stmt->keyVar);
@@ -1396,8 +1394,6 @@ public function processStmtNode(
 							if ($dimFetchNativeType->isSuperTypeOf($valueVarNativeType)->yes()) {
 								$dimFetchNativeType = $valueVarNativeType;
 							}
-						} elseif ($stmt->byRef && $originalValueExpr !== null) {
-							$dimFetchNativeType = $scopeWithIterableValueType->getNativeType($stmt->valueVar);
 						}
 						$arrayDimFetchLoopNativeTypes[] = $dimFetchNativeType;
 						$keyLoopNativeTypes[] = $scopeWithIterableValueType->getType($stmt->keyVar);