Finish implementing lazy deoptimization (ia32, x64). Ran tests with --deoptimize-alot.

runtime/vm/object.cc

Index: runtime/vm/object.cc
===================================================================
--- runtime/vm/object.cc	(revision 12092)
+++ runtime/vm/object.cc	(working copy)
@@ -6927,14 +6927,15 @@
 
 const char* PcDescriptors::KindAsStr(intptr_t index) const {
   switch (DescriptorKind(index)) {
-    case PcDescriptors::kDeoptBefore: return "deopt-before ";
-    case PcDescriptors::kDeoptAfter:  return "deopt-after  ";
-    case PcDescriptors::kDeoptIndex:  return "deopt-ix     ";
-    case PcDescriptors::kPatchCode:   return "patch        ";
-    case PcDescriptors::kIcCall:      return "ic-call      ";
-    case PcDescriptors::kFuncCall:    return "fn-call      ";
-    case PcDescriptors::kReturn:      return "return       ";
-    case PcDescriptors::kOther:       return "other        ";
+    case PcDescriptors::kDeoptBefore:   return "deopt-before ";
+    case PcDescriptors::kDeoptAfter:    return "deopt-after  ";
+    case PcDescriptors::kDeoptIndex:    return "deopt-ix     ";
+    case PcDescriptors::kPatchCode:     return "patch        ";
+    case PcDescriptors::kLazyDeoptJump: return "lazy-deopt   ";
+    case PcDescriptors::kIcCall:        return "ic-call      ";
+    case PcDescriptors::kFuncCall:      return "fn-call      ";
+    case PcDescriptors::kReturn:        return "return       ";
+    case PcDescriptors::kOther:         return "other        ";
   }
   UNREACHABLE();
   return "";
@@ -7032,6 +7033,16 @@
 }
 
 
+uword PcDescriptors::GetPcForKind(Kind kind) const {
+  for (intptr_t i = 0; i < Length(); i++) {
+    if (DescriptorKind(i) == kind) {
+      return PC(i);
+    }
+  }
+  return 0;
+}
+
+
 void Stackmap::SetCode(const dart::Code& code) const {
   StorePointer(&raw_ptr()->code_, code.raw());
 }
@@ -7600,15 +7611,16 @@
 
 uword Code::GetPatchCodePc() const {
   const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
-  for (intptr_t i = 0; i < descriptors.Length(); i++) {
-    if (descriptors.DescriptorKind(i) == PcDescriptors::kPatchCode) {
-      return descriptors.PC(i);
-    }
-  }
-  return 0;
+  return descriptors.GetPcForKind(PcDescriptors::kPatchCode);
 }
 
 
+uword Code::GetLazyDeoptPc() const {
+  const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
+  return descriptors.GetPcForKind(PcDescriptors::kLazyDeoptJump);
+}
+
+
 bool Code::ObjectExistsInArea(intptr_t start_offset,
                               intptr_t end_offset) const {
   for (intptr_t i = 0; i < this->pointer_offsets_length(); i++) {