test not stringable and bcmath

Author: staabm

src/Type/ObjectType.php

@@ -707,6 +707,14 @@ public function toArrayKey(): Type
 	public function toCoercedArgumentType(bool $strictTypes): Type
 	{
 		if (!$strictTypes) {
+			$classReflection = $this->getClassReflection();
+			if (
+				$classReflection === null
+				|| !$classReflection->hasNativeMethod('__toString')
+			) {
+				return $this;
+			}
+
 			return TypeCombinator::union($this, $this->toString());
 		}
 

tests/PHPStan/Analyser/nsrt/bug-12393b.php

@@ -306,7 +306,7 @@ public function doFoo(): void {
         assertType('null', $this->foo);
 
         $this->fooNonNull = $this->returnVoid();
-        assertType('int|null', $this->foo); // should be *ERROR*
+        assertType('int|null', $this->foo); // should be *NEVER*
     }
 
     public function returnVoid(): void {
@@ -680,11 +680,24 @@ public function doFoo(StringableFoo $foo): void {
         $this->foo = $foo;
         assertType('string', $this->foo);
     }
+
+    public function doFoo2(NotStringable $foo): void {
+        $this->foo = $foo;
+        assertType('*NEVER*', $this->foo);
+    }
+
+    public function doFoo3(\BcMath\Number $foo): void {
+        $this->foo = $foo;
+        assertType('non-empty-string&numeric-string', $this->foo);
+    }
+
     public function __toString(): string {
         return 'Foo';
     }
 }
 
+final class NotStringable {}
+
 class ObjectWithToStringMethod {
     private string $foo;