Add Handle/HandleScope and delete SirtRef.

Delete SirtRef and replaced it with Handle. Handles are value types
which wrap around StackReference*.

Renamed StackIndirectReferenceTable to HandleScope.

Added a scoped handle wrapper which wraps around an Object** and
restores it in its destructor.

Renamed Handle::get -> Get.

Bug: 8473721

Change-Id: Idbfebd4f35af629f0f43931b7c5184b334822c7a
diff --git a/compiler/utils/mips/assembler_mips.cc b/compiler/utils/mips/assembler_mips.cc
index 9001f8a..8001dcd 100644
--- a/compiler/utils/mips/assembler_mips.cc
+++ b/compiler/utils/mips/assembler_mips.cc
@@ -827,8 +827,8 @@
   UNIMPLEMENTED(FATAL) << "no mips implementation";
 }
 
-void MipsAssembler::CreateSirtEntry(ManagedRegister mout_reg,
-                                    FrameOffset sirt_offset,
+void MipsAssembler::CreateHandleScopeEntry(ManagedRegister mout_reg,
+                                    FrameOffset handle_scope_offset,
                                     ManagedRegister min_reg, bool null_allowed) {
   MipsManagedRegister out_reg = mout_reg.AsMips();
   MipsManagedRegister in_reg = min_reg.AsMips();
@@ -836,27 +836,27 @@
   CHECK(out_reg.IsCoreRegister()) << out_reg;
   if (null_allowed) {
     Label null_arg;
-    // Null values get a SIRT entry value of 0.  Otherwise, the SIRT entry is
-    // the address in the SIRT holding the reference.
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
     // e.g. out_reg = (handle == 0) ? 0 : (SP+handle_offset)
     if (in_reg.IsNoRegister()) {
       LoadFromOffset(kLoadWord, out_reg.AsCoreRegister(),
-                     SP, sirt_offset.Int32Value());
+                     SP, handle_scope_offset.Int32Value());
       in_reg = out_reg;
     }
     if (!out_reg.Equals(in_reg)) {
       LoadImmediate(out_reg.AsCoreRegister(), 0);
     }
     EmitBranch(in_reg.AsCoreRegister(), ZERO, &null_arg, true);
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
     Bind(&null_arg, false);
   } else {
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
   }
 }
 
-void MipsAssembler::CreateSirtEntry(FrameOffset out_off,
-                                    FrameOffset sirt_offset,
+void MipsAssembler::CreateHandleScopeEntry(FrameOffset out_off,
+                                    FrameOffset handle_scope_offset,
                                     ManagedRegister mscratch,
                                     bool null_allowed) {
   MipsManagedRegister scratch = mscratch.AsMips();
@@ -864,21 +864,21 @@
   if (null_allowed) {
     Label null_arg;
     LoadFromOffset(kLoadWord, scratch.AsCoreRegister(), SP,
-                   sirt_offset.Int32Value());
-    // Null values get a SIRT entry value of 0.  Otherwise, the sirt entry is
-    // the address in the SIRT holding the reference.
-    // e.g. scratch = (scratch == 0) ? 0 : (SP+sirt_offset)
+                   handle_scope_offset.Int32Value());
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
+    // e.g. scratch = (scratch == 0) ? 0 : (SP+handle_scope_offset)
     EmitBranch(scratch.AsCoreRegister(), ZERO, &null_arg, true);
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
     Bind(&null_arg, false);
   } else {
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
   }
   StoreToOffset(kStoreWord, scratch.AsCoreRegister(), SP, out_off.Int32Value());
 }
 
-// Given a SIRT entry, load the associated reference.
-void MipsAssembler::LoadReferenceFromSirt(ManagedRegister mout_reg,
+// Given a handle scope entry, load the associated reference.
+void MipsAssembler::LoadReferenceFromHandleScope(ManagedRegister mout_reg,
                                           ManagedRegister min_reg) {
   MipsManagedRegister out_reg = mout_reg.AsMips();
   MipsManagedRegister in_reg = min_reg.AsMips();
diff --git a/compiler/utils/mips/assembler_mips.h b/compiler/utils/mips/assembler_mips.h
index 75ee8b9..216cb41 100644
--- a/compiler/utils/mips/assembler_mips.h
+++ b/compiler/utils/mips/assembler_mips.h
@@ -238,20 +238,20 @@
   void GetCurrentThread(ManagedRegister tr) OVERRIDE;
   void GetCurrentThread(FrameOffset dest_offset, ManagedRegister mscratch) OVERRIDE;
 
-  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_reg to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed. in_reg holds a possibly stale reference
-  // that can be used to avoid loading the SIRT entry to see if the value is
+  // that can be used to avoid loading the handle scope entry to see if the value is
   // NULL.
-  void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset, ManagedRegister in_reg,
+  void CreateHandleScopeEntry(ManagedRegister out_reg, FrameOffset handlescope_offset, ManagedRegister in_reg,
                        bool null_allowed) OVERRIDE;
 
-  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_off to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed.
-  void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset, ManagedRegister mscratch,
+  void CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handlescope_offset, ManagedRegister mscratch,
                        bool null_allowed) OVERRIDE;
 
-  // src holds a SIRT entry (Object**) load this into dst
-  void LoadReferenceFromSirt(ManagedRegister dst, ManagedRegister src) OVERRIDE;
+  // src holds a handle scope entry (Object**) load this into dst
+  void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) OVERRIDE;
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
   // know that src may not be null.