add more tests and add PHP version check

Author: canvural

src/Analyser/NodeScopeResolver.php

@@ -3619,10 +3619,12 @@ static function (): void {
 			$exprType = $scope->getType($expr->expr);
 			$toStringMethod = $scope->getMethodReflection($exprType, '__toString');
 			if ($toStringMethod !== null) {
-				if ($toStringMethod->getThrowType() !== null) {
-					$throwPoints[] = InternalThrowPoint::createExplicit($scope, $toStringMethod->getThrowType(), $expr, false);
-				} else {
-					$throwPoints[] = InternalThrowPoint::createImplicit($scope, $expr);
+				if ($this->phpVersion->throwsOnStringCast()) {
+					if ($toStringMethod->getThrowType() !== null) {
+						$throwPoints[] = InternalThrowPoint::createExplicit($scope, $toStringMethod->getThrowType(), $expr, false);
+					} else {
+						$throwPoints[] = InternalThrowPoint::createImplicit($scope, $expr);
+					}
 				}
 
 				if (!$toStringMethod->hasSideEffects()->no()) {

src/Php/PhpVersion.php

@@ -479,4 +479,9 @@ public function deprecatesIncOnNonNumericString(): bool
 		return $this->versionId >= 80500;
 	}
 
+    public function throwsOnStringCast(): bool
+    {
+		return $this->versionId >= 70400;
+    }
+
 }

tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php

@@ -645,7 +645,12 @@ public function testPropertyHooks(): void
 
 	public function testBug13806(): void
 	{
-		$this->analyse([__DIR__ . '/data/bug-13806.php'], []);
+		$this->analyse([__DIR__ . '/data/bug-13806.php'], [
+			[
+				'Dead catch - InvalidArgumentException is never thrown in the try block.',
+				16,
+			],
+		]);
 	}
 
 }

tests/PHPStan/Rules/Exceptions/data/bug-13806.php

@@ -2,14 +2,24 @@
 
 namespace Bug13806;
 
-function doFoo(MyString $myVariable): void
+function doFoo(MyString $myVariable, MyStringVoid $string, $mixed): void
 {
 	try {
 		(string) $myVariable;
-	} catch (\InvalidArgumentException) {
+	} catch (\InvalidArgumentException $e) {
 		// Reported as dead catch, even though the `__toString()` method
 		// in `$myVariable` might throw an exception.
 	}
+
+	try {
+		(string) $string;
+	} catch (\InvalidArgumentException $e) {
+	}
+
+	try {
+		(string) $mixed;
+	} catch (\InvalidArgumentException $e) {
+	}
 }
 
 class MyString {
@@ -18,3 +28,11 @@ public function __toString() {
 		throw new \InvalidArgumentException();
 	}
 }
+
+class MyStringVoid {
+	/** @throws void */
+	public function __toString()
+	{
+		throw new \InvalidArgumentException();
+	}
+}