ART: IRT refactor

IRT creation might fail. Add a path that allows to bypass the aborts
and instead signal validity. Hide this path with a private constructor,
rewrite users to use a static Create method.

Bug: 20110201

Change-Id: I440499c3372cd7557eb970b70ce2c4543da520e4
diff --git a/runtime/indirect_reference_table.h b/runtime/indirect_reference_table.h
index 25b0281..0072184 100644
--- a/runtime/indirect_reference_table.h
+++ b/runtime/indirect_reference_table.h
@@ -258,10 +258,15 @@
 
 class IndirectReferenceTable {
  public:
-  IndirectReferenceTable(size_t initialCount, size_t maxCount, IndirectRefKind kind);
+  // WARNING: When using with abort_on_error = false, the object may be in a partially
+  //          initialized state. Use IsValid() to check.
+  IndirectReferenceTable(size_t initialCount, size_t maxCount, IndirectRefKind kind,
+                         bool abort_on_error = true);
 
   ~IndirectReferenceTable();
 
+  bool IsValid() const;
+
   /*
    * Add a new entry.  "obj" must be a valid non-NULL object reference.
    *