Simplify NonNullabilityHelper (phpstan#5158)

Author: staabm

src/Analyser/ExprHandler/Helper/NonNullabilityHelper.php

@@ -28,12 +28,7 @@ public function ensureShallowNonNullability(MutatingScope $scope, Scope $origina
 			return new EnsuredNonNullabilityResult($scope, []);
 		}
 
-		// keep certainty
-		$certainty = TrinaryLogic::createYes();
 		$hasExpressionType = $originalScope->hasExpressionType($exprToSpecify);
-		if (!$hasExpressionType->no()) {
-			$certainty = $hasExpressionType;
-		}
 
 		$exprTypeWithoutNull = TypeCombinator::removeNull($exprType);
 		if ($exprType->equals($exprTypeWithoutNull)) {
@@ -63,6 +58,12 @@ public function ensureShallowNonNullability(MutatingScope $scope, Scope $origina
 			);
 		}
 
+		// keep certainty
+		$certainty = TrinaryLogic::createYes();
+		if (!$hasExpressionType->no()) {
+			$certainty = $hasExpressionType;
+		}
+
 		$nativeType = $scope->getNativeType($exprToSpecify);
 		$specifiedExpressions[] = new EnsuredNonNullabilityResultExpression($exprToSpecify, $exprType, $nativeType, $certainty);
 		$scope = $scope->specifyExpressionType(