resolve feedback

This (mostly) resolves https://github.com/phpstan/phpstan-src/pull/3613/files#r1835477700 in that the error reappears, but loses the lowercase-string portion of the error string.

Author: pmjones

src/Reflection/InitializerExprTypeResolver.php

@@ -482,13 +482,7 @@ public function resolveConcatType(Type $left, Type $right): Type
 			$accessoryTypes[] = new AccessoryLiteralStringType();
 		}
 
-		if ($leftStringType->isLowercaseString()->and($rightStringType->isLowercaseString())->yes()) {
-			$accessoryTypes[] = new AccessoryLowercaseStringType();
-		}
-
-		if ($leftStringType->isUppercaseString()->and($rightStringType->isUppercaseString())->yes()) {
-			$accessoryTypes[] = new AccessoryUppercaseStringType();
-		}
+		$this->appendAccessoryCasedStringTypes($leftStringType, $rightStringType, $accessoryTypes);
 
 		$leftNumericStringNonEmpty = TypeCombinator::remove($leftStringType, new ConstantStringType(''));
 		if ($leftNumericStringNonEmpty->isNumericString()->yes()) {
@@ -524,6 +518,26 @@ public function resolveConcatType(Type $left, Type $right): Type
 		return new StringType();
 	}
 
+	protected function appendAccessoryCasedStringTypes($leftStringType, $rightStringType, array &$accessoryTypes): void
+	{
+		$lower = $leftStringType->isLowercaseString()->and($rightStringType->isLowercaseString())->yes();
+		$upper = $leftStringType->isUppercaseString()->and($rightStringType->isUppercaseString())->yes();
+
+		if ($lower && $upper) {
+			return;
+		}
+
+		if ($lower) {
+			$accessoryTypes[] = new AccessoryLowercaseStringType();
+			return;
+		}
+
+		if ($upper) {
+			$accessoryTypes[] = new AccessoryUppercaseStringType();
+			return;
+		}
+	}
+
 	/**
 	 * @param callable(Expr): Type $getTypeCallback
 	 */

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -635,6 +635,10 @@ public function testArrayUdiffCallback(): void
 				'Parameter #3 $data_comp_func of function array_udiff expects callable(1|2|3|4|5|6, 1|2|3|4|5|6): int, Closure(string, string): string given.',
 				6,
 			],
+			[
+				'Parameter #3 $data_comp_func of function array_udiff expects callable(1|2|3|4|5|6, 1|2|3|4|5|6): int, Closure(int, int): (literal-string&non-falsy-string&numeric-string) given.',
+				14,
+			],
 			[
 				'Parameter #1 $arr1 of function array_udiff expects array<string>, null given.',
 				20,