Emit virtual Assign node for List_ destructuring in foreach value position

- When a `foreach` uses array destructuring in the value position
  (e.g. `foreach ($arr as ['key' => $val])`), `ArrayDestructuringRule`
  was never invoked because no `Assign` node was emitted for it to match.
- In `NodeScopeResolver::processStmtNode`, alongside the existing
  `VariableAssignNode` emission for simple variable foreach values,
  emit a virtual `Assign(List_, GetIterableValueTypeExpr)` node when
  the value var is a `List_`. This causes `ArrayDestructuringRule` to
  fire and report nonexistent offsets.
- The virtual node is emitted once before the loop convergence iterations,
  avoiding duplicate error reports.
- Covers both `[]` and `list()` syntax, string/integer keys, and nested
  destructuring patterns.
- Analogous cases probed and found not broken: foreach key destructuring
  (not valid PHP), regular assignment destructuring (already worked),
  assignment inside foreach body (already worked).

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -1240,6 +1240,10 @@ public function processStmtNode(
 
 			if ($stmt->valueVar instanceof Variable) {
 				$this->callNodeCallback($nodeCallback, new VariableAssignNode($stmt->valueVar, new GetIterableValueTypeExpr($stmt->expr)), $originalScope, $storage);
+			} elseif ($stmt->valueVar instanceof List_) {
+				$virtualAssign = new Assign($stmt->valueVar, new GetIterableValueTypeExpr($stmt->expr));
+				$virtualAssign->setAttributes($stmt->valueVar->getAttributes());
+				$this->callNodeCallback($nodeCallback, $virtualAssign, $scope, $storage);
 			}
 
 			$originalStorage = $storage;

tests/PHPStan/Rules/Arrays/ArrayDestructuringRuleTest.php

@@ -68,6 +68,40 @@ public function testBug14270(): void
 		$this->analyse([__DIR__ . '/data/bug-14270.php'], []);
 	}
 
+	public function testBug8075(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-8075.php'], [
+			[
+				'Offset \'b\' does not exist on array{a: 0}.',
+				12,
+			],
+			[
+				'Offset \'b\' does not exist on array{a: 0}.',
+				14,
+			],
+			[
+				'Offset \'b\' does not exist on array{a: 0}.',
+				17,
+			],
+			[
+				'Offset \'b\' does not exist on array{a: 0}.',
+				24,
+			],
+			[
+				'Offset \'missing\' does not exist on array{name: string, age: int}.',
+				36,
+			],
+			[
+				'Offset 2 does not exist on array{string, int}.',
+				48,
+			],
+			[
+				'Offset \'z\' does not exist on array{x: int, y: int}.',
+				60,
+			],
+		]);
+	}
+
 	#[RequiresPhp('>= 8.0.0')]
 	public function testRuleWithNullsafeVariant(): void
 	{

tests/PHPStan/Rules/Arrays/data/bug-8075.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace Bug8075;
+
+class Foo
+{
+
+	public function doFoo(): void
+	{
+		$arr = [['a' => 0]];
+
+		['b' => $val] = $arr[0]; // error - works
+
+		foreach ($arr as ['b' => $valueB]) { // error - should be reported
+		}
+
+		foreach ($arr as ['b' => $valueB, 'a' => $valueA]) { // error on 'b'
+		}
+
+		foreach ($arr as ['a' => $valueA]) { // no error - 'a' exists
+		}
+
+		foreach ($arr as $item) {
+			['b' => $valueB] = $item; // error - works
+		}
+	}
+
+	/**
+	 * @param array<int, array{name: string, age: int}> $people
+	 */
+	public function doBar(array $people): void
+	{
+		foreach ($people as ['name' => $name, 'age' => $age]) { // no error
+		}
+
+		foreach ($people as ['name' => $name, 'missing' => $missing]) { // error on 'missing'
+		}
+	}
+
+	/**
+	 * @param list<array{0: string, 1: int}> $tuples
+	 */
+	public function doBaz(array $tuples): void
+	{
+		foreach ($tuples as [$first, $second]) { // no error
+		}
+
+		foreach ($tuples as [$first, $second, $third]) { // error on offset 2
+		}
+	}
+
+	/**
+	 * @param list<array{a: array{x: int, y: int}}> $nested
+	 */
+	public function doNested(array $nested): void
+	{
+		foreach ($nested as ['a' => ['x' => $x, 'y' => $y]]) { // no error
+		}
+
+		foreach ($nested as ['a' => ['x' => $x, 'z' => $z]]) { // error on 'z'
+		}
+	}
+
+}