Add tables to map between callee saves and vregs

Also added function to return sp-relative offset for Dalvik
virtual registers using Method*

[Note: must be matched with corresponding libcore change to
reflect new field in Method]

Change-Id: Id739908c6232ce60763d8199bc05111e960da46e
diff --git a/src/compiler.h b/src/compiler.h
index 26b33b8..50447db 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -45,6 +45,7 @@
   void CompileDexFile(const ClassLoader* class_loader, const DexFile& dex_file);
   void CompileClass(Class* klass);
   void CompileMethod(Method* klass);
+  int oatVRegOffsetFromMethod(Method* method, int reg);
 
   // After compiling, walk all the DexCaches and set the code and
   // method pointers of CodeAndDirectMethods entries in the DexCaches.