Don't add barriers to clinit methods.

Change-Id: I13e6c008feb8c19e452d6e2f88b2bbbcac997de5
(cherry picked from commit 9fc16eb43fe938f0cddb13638bd7cbc2ea9534a2)
diff --git a/compiler/driver/dex_compilation_unit.h b/compiler/driver/dex_compilation_unit.h
index 5bf0086..465139b 100644
--- a/compiler/driver/dex_compilation_unit.h
+++ b/compiler/driver/dex_compilation_unit.h
@@ -80,6 +80,10 @@
     return access_flags_;
   }
 
+  bool IsConstructor() const {
+    return ((access_flags_ & kAccConstructor) != 0);
+  }
+
   bool IsNative() const {
     return ((access_flags_ & kAccNative) != 0);
   }