Generate our own sun.misc.Unsafe if it is not available (#4124)

* Generate our own sun.misc.Unsafe if it is not available

* skip generating invokeCleaner method

* grpc isn't shaded so setting system property doesn't affect only our bundled copy

* generate invokeCleaner when it is present in internal unsafe

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/AgentClassLoader.java

@@ -145,13 +145,17 @@ protected Class<?> findClass(String name) throws ClassNotFoundException {
       }
 
       definePackageIfNeeded(name);
-      return defineClass(name, bytes, 0, bytes.length, codeSource);
+      return defineClass(name, bytes);
     }
 
     // find class from agent initializer jar
     return super.findClass(name);
   }
 
+  public Class<?> defineClass(String name, byte[] bytes) {
+    return defineClass(name, bytes, 0, bytes.length, codeSource);
+  }
+
   private byte[] getJarEntryBytes(JarEntry jarEntry) throws IOException {
     int size = (int) jarEntry.getSize();
     byte[] buffer = new byte[size];

javaagent-tooling/build.gradle.kts

@@ -9,6 +9,7 @@ dependencies {
   implementation(project(":javaagent-bootstrap"))
   implementation(project(":javaagent-extension-api"))
   implementation(project(":javaagent-instrumentation-api"))
+  implementation(project(":javaagent-tooling:javaagent-tooling-java9"))
   implementation(project(":instrumentation-api"))
   implementation(project(":instrumentation-api-annotation-support"))
   implementation(project(":muzzle"))

javaagent-tooling/javaagent-tooling-java9/build.gradle.kts

@@ -0,0 +1,19 @@
+plugins {
+  id("otel.java-conventions")
+  id("otel.publish-conventions")
+}
+
+group = "io.opentelemetry.javaagent"
+
+dependencies {
+  implementation(project(":javaagent-bootstrap"))
+
+  implementation("net.bytebuddy:byte-buddy")
+  implementation("org.slf4j:slf4j-api")
+
+  testImplementation("net.bytebuddy:byte-buddy-agent")
+}
+
+otelJava {
+  minJavaVersionSupported.set(JavaVersion.VERSION_1_9)
+}