feat(DowngradePhp73JsonConstRector): throw behavior

* Try to properly downgrade the throw behavior removed from `json_encode` and `json_decode`
  with an alternative code snippet added after the function node.
* This is a partial solution that only handles when the flags are directly set in the function call.

rules-tests/DowngradePhp73/Rector/ConstFetch/DowngradePhp73JsonConstRector/Fixture/add_throw_on_json_decode_error.php.inc

@@ -0,0 +1,99 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp73\Rector\ConstFetch\DowngradePhp73JsonConstRector\Fixture;
+
+// Class
+class DowngradePhp73JsonConstRectorFixture
+{
+    public function method_json_decode(string $json): string | bool
+    {
+        try {
+            $payload = json_decode($json, null, 512, JSON_THROW_ON_ERROR);
+            return $payload;
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+
+    public function method_json_decode_multi_flags(string $json): string | bool
+    {
+        try {
+            $payload = json_decode($json, null, 512, JSON_OBJECT_AS_ARRAY | JSON_THROW_ON_ERROR);
+            return $payload;
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+}
+
+// Function
+function func_json_decode(string $json): string | bool
+{
+    try {
+        $payload = json_decode($json, null, 512, JSON_THROW_ON_ERROR);
+        return $payload;
+    } catch (\Exception $e) {
+        return false;
+    }
+}
+
+// Standalone
+$decode = json_decode($json, null, 512, JSON_THROW_ON_ERROR);
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp73\Rector\ConstFetch\DowngradePhp73JsonConstRector\Fixture;
+
+// Class
+class DowngradePhp73JsonConstRectorFixture
+{
+    public function method_json_decode(string $json): string | bool
+    {
+        try {
+            $payload = json_decode($json, null, 512, 0);
+            if (json_last_error() !== JSON_ERROR_NONE) {
+                throw new \Exception(json_last_error_msg());
+            }
+            return $payload;
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+
+    public function method_json_decode_multi_flags(string $json): string | bool
+    {
+        try {
+            $payload = json_decode($json, null, 512, JSON_OBJECT_AS_ARRAY);
+            if (json_last_error() !== JSON_ERROR_NONE) {
+                throw new \Exception(json_last_error_msg());
+            }
+            return $payload;
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+}
+
+// Function
+function func_json_decode(string $json): string | bool
+{
+    try {
+        $payload = json_decode($json, null, 512, 0);
+        if (json_last_error() !== JSON_ERROR_NONE) {
+            throw new \Exception(json_last_error_msg());
+        }
+        return $payload;
+    } catch (\Exception $e) {
+        return false;
+    }
+}
+
+// Standalone
+$decode = json_decode($json, null, 512, 0);
+if (json_last_error() !== JSON_ERROR_NONE) {
+    throw new \Exception(json_last_error_msg());
+}
+
+?>

rules-tests/DowngradePhp73/Rector/ConstFetch/DowngradePhp73JsonConstRector/Fixture/add_throw_on_json_encode_error.php.inc

@@ -0,0 +1,93 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp73\Rector\ConstFetch\DowngradePhp73JsonConstRector\Fixture;
+
+// Class
+class DowngradePhp73JsonConstRectorFixture
+{
+    public function method_json_encode(string $json): string | bool
+    {
+        try {
+            json_encode($json, JSON_THROW_ON_ERROR);
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+
+    public function method_json_encode_multi_flags(string $json): string | bool
+    {
+        try {
+            json_encode($json, JSON_THROW_ON_ERROR | JSON_PRETTY_PRINT);
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+}
+
+// Function
+function func_json_encode(string $json): string | bool
+{
+    try {
+        json_encode($json, JSON_THROW_ON_ERROR);
+    } catch (\Exception $e) {
+        return false;
+    }
+}
+
+// Standalone
+json_encode($json, JSON_THROW_ON_ERROR);
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp73\Rector\ConstFetch\DowngradePhp73JsonConstRector\Fixture;
+
+// Class
+class DowngradePhp73JsonConstRectorFixture
+{
+    public function method_json_encode(string $json): string | bool
+    {
+        try {
+            json_encode($json, 0);
+            if (json_last_error() !== JSON_ERROR_NONE) {
+                throw new \Exception(json_last_error_msg());
+            }
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+
+    public function method_json_encode_multi_flags(string $json): string | bool
+    {
+        try {
+            json_encode($json, JSON_PRETTY_PRINT);
+            if (json_last_error() !== JSON_ERROR_NONE) {
+                throw new \Exception(json_last_error_msg());
+            }
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+}
+
+// Function
+function func_json_encode(string $json): string | bool
+{
+    try {
+        json_encode($json, 0);
+        if (json_last_error() !== JSON_ERROR_NONE) {
+            throw new \Exception(json_last_error_msg());
+        }
+    } catch (\Exception $e) {
+        return false;
+    }
+}
+
+// Standalone
+json_encode($json, 0);
+if (json_last_error() !== JSON_ERROR_NONE) {
+    throw new \Exception(json_last_error_msg());
+}
+
+?>

rules-tests/DowngradePhp73/Rector/ConstFetch/DowngradePhp73JsonConstRector/Fixture/in_bitwise.php.inc

@@ -25,6 +25,9 @@ class InBitwise
     public function run($argument)
     {
         $argument = json_encode($argument, JSON_UNESCAPED_SLASHES);
+        if (json_last_error() !== JSON_ERROR_NONE) {
+            throw new \Exception(json_last_error_msg());
+        }
     }
 }