Initialize GBCExpander with NULL.

Change-Id: If7b94cb900bddb763d8b95506232d24aaa3fb7f8
diff --git a/src/compiler_llvm/gbc_expander.cc b/src/compiler_llvm/gbc_expander.cc
index 672014c..c28384a 100644
--- a/src/compiler_llvm/gbc_expander.cc
+++ b/src/compiler_llvm/gbc_expander.cc
@@ -54,7 +54,6 @@
   uint32_t shadow_frame_size_;
 
  private:
-  // TODO: Init these fields
   Compiler* compiler_;
 
   const DexFile* dex_file_;
@@ -341,7 +340,12 @@
 
   GBCExpanderPass(const IntrinsicHelper& intrinsic_helper, IRBuilder& irb)
       : llvm::FunctionPass(ID), intrinsic_helper_(intrinsic_helper), irb_(irb),
-        context_(irb.getContext()), rtb_(irb.Runtime())
+        context_(irb.getContext()), rtb_(irb.Runtime()),
+
+        // TODO: Initialize these fields correctly.
+        shadow_frame_(NULL), old_shadow_frame_(NULL), shadow_frame_size_(0),
+        compiler_(NULL), dex_file_(NULL), dex_cache_(NULL), code_item_(NULL),
+        oat_compilation_unit_(NULL), method_idx_(-1u), func_(NULL)
   { }
 
   bool runOnFunction(llvm::Function& func);