fix union types

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -1589,7 +1589,6 @@ private function getConditionalSpecifiedTypes(
 				$argumentExpr instanceof Node\Scalar
 				|| ($argumentExpr instanceof ConstFetch && in_array(strtolower($argumentExpr->name->toString()), ['true', 'false', 'null'], true))
 			)
-			&& $targetType->isConstantScalarValue()->yes()
 		) {
 			return null;
 		}

tests/PHPStan/Rules/Comparison/data/check-type-function-call.php

@@ -99,10 +99,10 @@ public function test(string $str, float $float)
 		if (is_numeric($str)) {
 
 		}
-		if (is_numeric('123')) {
+		$x='123'; if (is_numeric($x)) {
 
 		}
-		if (is_numeric('blabla')) {
+		$y='blabla'; if (is_numeric($y)) {
 
 		}
 
@@ -715,8 +715,8 @@ class AssertIsNumeric
 	public function doFoo(string $str, float $float)
 	{
 		assert(is_numeric($str));
-		assert(is_numeric('123'));
-		assert(is_numeric('blabla'));
+		$x='123'; assert(is_numeric($x));
+		$y='blabla'; assert(is_numeric($y));
 
 		$isNumeric = $float;
 		if (doFoo()) {