Fix memory leak in compiler

Fixes jni internal test which is failing TOT on Nakasi.

Change-Id: Ie1d8256bb8719554737c6602cd14c6527c020869
diff --git a/src/compiler.cc b/src/compiler.cc
index b0d373b..1be7b75 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -389,6 +389,7 @@
     MutexLock mu(self, compiled_methods_lock_);
     STLDeleteElements(&methods_to_patch_);
   }
+  CHECK_PTHREAD_CALL(pthread_key_delete, (tls_key_), "delete tls key");
 #if defined(ART_USE_LLVM_COMPILER)
   // Uninitialize compiler_context_
   typedef void (*UninitCompilerContextFn)(Compiler&);