Add a reference table implementation.

This is suitable for pinned array references and the like.

I've also brought in some of the human-readable type printing stuff
for the benefit of the reference table dumping code.

This patch includes tests, but doesn't yet wire anything up.

Change-Id: Iaf6066201bbd254e033dee4fd0b8dfd0bc17afa9
diff --git a/src/utils.h b/src/utils.h
index 842db63..ea51d1e 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -5,10 +5,13 @@
 
 #include "globals.h"
 #include "logging.h"
+#include "stringpiece.h"
 #include "stringprintf.h"
 
 namespace art {
 
+class Object;
+
 template<typename T>
 static inline bool IsPowerOfTwo(T x) {
   return (x & (x - 1)) == 0;
@@ -132,6 +135,17 @@
   return result;
 }
 
+// Return a newly-allocated string containing a human-readable equivalent
+// of 'descriptor'. So "I" would be "int", "[[I" would be "int[][]",
+// "[Ljava/lang/String;" would be "java.lang.String[]", and so forth.
+std::string PrettyDescriptor(const StringPiece& descriptor);
+
+// Returns a human-readable string form of the name of the class of
+// the given object. So given a java.lang.String, the output would
+// be "java.lang.String". Given an array of int, the output would be "int[]".
+// Given String.class, the output would be "java.lang.Class<java.lang.String>".
+std::string PrettyType(const Object* obj);
+
 }  // namespace art
 
 #endif  // ART_SRC_UTILS_H_