ArrayShapeMatcher - Fix alternations containing a $-only case

Author: staabm

src/Type/Regex/RegexGroupParser.php

@@ -460,7 +460,7 @@ private function walkGroupAst(
 					$isNumeric = TrinaryLogic::createYes();
 				}
 
-				if (!$inOptionalQuantification) {
+				if (!$inOptionalQuantification && $literalValue !== '') {
 					$isNonEmpty = TrinaryLogic::createYes();
 				}
 			}

tests/PHPStan/Analyser/nsrt/preg_match_shapes.php

@@ -746,3 +746,10 @@ function bug11490b (string $expression): void {
 	}
 }
 
+function bug11622 (string $expression): void {
+	$matches = [];
+
+	if (preg_match('/^abc(def|$)/', $expression, $matches) === 1) {
+		assertType("array{string, string}", $matches);
+	}
+}