Reproduce ThresholdFilter GraalVM issue

This change reproduces the issue described in apache/logging-log4j2#3871, where configurations that include `ThresholdFilter` (or any other Log4j filter) fail to work correctly when building a GraalVM native image.

The root cause is a mismatch in how parameter types are represented in `reflect-config.json`:

* The existing metadata stores parameter types using their canonical class name (JLS §6.7).
* However, GraalVM expects the binary class name (JLS §13.1).
  This is especially relevant for nested types:

  * Canonical name: `org.apache.logging.log4j.core.Filter.Result`
  * Binary name: `org.apache.logging.log4j.core.Filter$Result`
* For array types, GraalVM accepts either:

  * the JVM descriptor form (`[L<component_type>;`), or
  * the Java-like form (`<component_type>[]`).

This PR introduces tests that intentionally fail for the `log4j-core` and `log4j-core-jtl` profiles, because they rely on the embedded reachability metadata in Log4j Core, which currently uses canonical names.
In contrast, the `log4j-core-minimal` and `log4j-core-jtl-minimal` profiles rely on manually generated metadata, which has been updated in this PR to use the expected binary names and now works correctly under GraalVM.

Author: ppkarwasz

log4j-samples-graalvm/src/main/resources/log4j2-jtl.xml

@@ -26,6 +26,14 @@
   </Appenders>
   <Loggers>
     <Root level="TRACE">
+      <!--
+        Added solely to verify the reachability-metadata regression (issue #3871).
+        This configuration is not intended for production use: relying on ThresholdFilter
+        instead of the more efficient built-in level checks is discouraged.
+
+        See: https://github.com/apache/logging-log4j2/issues/3871
+      -->
+      <ThresholdFilter level="DEBUG"/>
       <AppenderRef ref="FILE"/>
     </Root>
   </Loggers>

log4j-samples-graalvm/src/main/resources/log4j2.xml

@@ -26,6 +26,14 @@
   </Appenders>
   <Loggers>
     <Root level="TRACE">
+      <!--
+        Added solely to verify the reachability-metadata regression (issue #3871).
+        This configuration is not intended for production use: relying on ThresholdFilter
+        instead of the more efficient built-in level checks is discouraged.
+
+        See: https://github.com/apache/logging-log4j2/issues/3871
+      -->
+      <ThresholdFilter level="DEBUG"/>
       <AppenderRef ref="FILE"/>
     </Root>
   </Loggers>

log4j-samples-graalvm/src/reachability-metadata/log4j-core-jtl-minimal/Log4j2Plugins.json

@@ -110,6 +110,15 @@
       "builderHierarchy": [
         "org.apache.logging.log4j.layout.template.json.JsonTemplateLayout$EventTemplateAdditionalField$Builder"
       ]
+    },
+    "org.apache.logging.log4j.core.filter.ThresholdFilter": {
+      "pluginNames": [
+        "thresholdfilter"
+      ],
+      "elementName": "filter",
+      "printable": true,
+      "defer": false,
+      "builderHierarchy": []
     }
   },
   "jsontemplateresolverfactory": {

log4j-samples-graalvm/src/reachability-metadata/log4j-core-jtl-minimal/resources/META-INF/native-image/org.apache.logging.log4j/log4j-core/reflect-config.json

@@ -628,5 +628,19 @@
         "name": "propertyArray"
       }
     ]
+  },
+  {
+    "name": "org.apache.logging.log4j.core.filter.ThresholdFilter",
+    "methods": [
+      {
+        "name": "createFilter",
+        "parameterTypes": [
+          "org.apache.logging.log4j.Level",
+          "org.apache.logging.log4j.core.Filter$Result",
+          "org.apache.logging.log4j.core.Filter$Result"
+        ]
+      }
+    ],
+    "fields": []
   }
-]
+]

log4j-samples-graalvm/src/reachability-metadata/log4j-core-jtl-minimal/resources/META-INF/org/apache/logging/log4j/core/config/plugins/Log4j2Plugins.dat

@@ -506,6 +506,15 @@
       "builderHierarchy": [
         "org.apache.logging.log4j.core.layout.PatternLayout$Builder"
       ]
+    },
+    "org.apache.logging.log4j.core.filter.ThresholdFilter": {
+      "pluginNames": [
+        "thresholdfilter"
+      ],
+      "elementName": "filter",
+      "printable": true,
+      "defer": false,
+      "builderHierarchy": []
     }
   },
   "typeconverter": {

log4j-samples-graalvm/src/reachability-metadata/log4j-core-minimal/Log4j2Plugins.json

@@ -1316,5 +1316,19 @@
       }
     ],
     "fields": []
+  },
+  {
+    "name": "org.apache.logging.log4j.core.filter.ThresholdFilter",
+    "methods": [
+      {
+        "name": "createFilter",
+        "parameterTypes": [
+          "org.apache.logging.log4j.Level",
+          "org.apache.logging.log4j.core.Filter$Result",
+          "org.apache.logging.log4j.core.Filter$Result"
+        ]
+      }
+    ],
+    "fields": []
   }
-]
+]

log4j-samples-graalvm/src/reachability-metadata/log4j-core-minimal/resources/META-INF/native-image/org.apache.logging.log4j/log4j-core/reflect-config.json

@@ -33,7 +33,7 @@
  */
 class JsonTemplateLayoutIT {
 
-    static final String[] STANDARD_LEVELS = {"ERROR", "WARN", "INFO", "DEBUG", "TRACE"};
+    static final String[] STANDARD_LEVELS = {"ERROR", "WARN", "INFO", "DEBUG"};
 
     @Test
     void verifyStdOut() {

log4j-samples-graalvm/src/reachability-metadata/log4j-core-minimal/resources/META-INF/org/apache/logging/log4j/core/config/plugins/Log4j2Plugins.dat

@@ -32,7 +32,7 @@
  */
 class StandardIT {
 
-    static final String[] STANDARD_LEVELS = {"ERROR", "WARN", "INFO", "DEBUG", "TRACE"};
+    static final String[] STANDARD_LEVELS = {"ERROR", "WARN", "INFO", "DEBUG"};
 
     @Test
     void verifyStdOut() {