ART: Clean up IndirectReferenceTable

Introduce constants and move some functions into the
IndirectReferenceTable class.

Slightly change IndirectRef encoding to be more obvious (and slighly
more optimized when decoding).

Bug: 32125344
Test: m test-art-host
Change-Id: I05819eccb733b611de582fb8d7151f1a110c305a
diff --git a/runtime/thread.cc b/runtime/thread.cc
index e47ccc0..ace5e67 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -1860,7 +1860,7 @@
     return nullptr;
   }
   IndirectRef ref = reinterpret_cast<IndirectRef>(obj);
-  IndirectRefKind kind = GetIndirectRefKind(ref);
+  IndirectRefKind kind = IndirectReferenceTable::GetIndirectRefKind(ref);
   ObjPtr<mirror::Object> result;
   bool expect_null = false;
   // The "kinds" below are sorted by the frequency we expect to encounter them.
@@ -1902,7 +1902,7 @@
 bool Thread::IsJWeakCleared(jweak obj) const {
   CHECK(obj != nullptr);
   IndirectRef ref = reinterpret_cast<IndirectRef>(obj);
-  IndirectRefKind kind = GetIndirectRefKind(ref);
+  IndirectRefKind kind = IndirectReferenceTable::GetIndirectRefKind(ref);
   CHECK_EQ(kind, kWeakGlobal);
   return tlsPtr_.jni_env->vm->IsWeakGlobalCleared(const_cast<Thread*>(this), ref);
 }