Replace initializedNonEmpty with initializedEmpty set in createFromConstantArray

Instead of setting initializedNonEmpty=true in createEmpty(), use the
inverse property initializedEmpty and set it in createFromConstantArray()
when the source array has no keys. This is cleaner because createEmpty()
is always used to build arrays that will have items added, while the only
truly "initialized empty" case is createFromConstantArray with an empty
ConstantArrayType (representing $a = [] imperative assignment).

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

Author: phpstan-bot

src/Type/Constant/ConstantArrayTypeBuilder.php

@@ -42,7 +42,7 @@ final class ConstantArrayTypeBuilder
 
 	private bool $oversized = false;
 
-	private bool $initializedNonEmpty = false;
+	private bool $initializedEmpty = false;
 
 	/**
 	 * @param list<Type> $keyTypes
@@ -62,10 +62,7 @@ private function __construct(
 
 	public static function createEmpty(): self
 	{
-		$self = new self([], [], [0], [], TrinaryLogic::createYes());
-		$self->initializedNonEmpty = true;
-
-		return $self;
+		return new self([], [], [0], [], TrinaryLogic::createYes());
 	}
 
 	public static function createFromConstantArray(ConstantArrayType $startArrayType): self
@@ -78,6 +75,10 @@ public static function createFromConstantArray(ConstantArrayType $startArrayType
 			$startArrayType->isList(),
 		);
 
+		if (count($startArrayType->getKeyTypes()) === 0) {
+			$builder->initializedEmpty = true;
+		}
+
 		if (count($startArrayType->getKeyTypes()) > self::ARRAY_COUNT_LIMIT) {
 			$builder->degradeToGeneralArray(true);
 		}
@@ -441,7 +442,7 @@ private function shouldUpdateAutoIndex(int $offsetValue, int $max): bool
 			return true;
 		}
 
-		return $this->initializedNonEmpty && $phpVersion->updatesAutoIncrementKeyForNegativeValuesInNonEmptyInitializer();
+		return !$this->initializedEmpty && $phpVersion->updatesAutoIncrementKeyForNegativeValuesInNonEmptyInitializer();
 	}
 
 }