Remove the mutex lock from Materialize().

Change-Id: I98ebee1358e67085574cacbeb92744f86b1fac0f
diff --git a/src/compiler_llvm/compiler_llvm.h b/src/compiler_llvm/compiler_llvm.h
index 8bb053e..a6cf966 100644
--- a/src/compiler_llvm/compiler_llvm.h
+++ b/src/compiler_llvm/compiler_llvm.h
@@ -109,7 +109,7 @@
  private:
   void EnsureCompilationUnit();
 
-  void Materialize();
+  void Materialize(CompilationUnit* cunit);
 
   void LoadElfFromCompilationUnit(const CompilationUnit* cunit);