NewGC: Merge bleeding edge up to 9009.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
===================================================================
--- src/x64/lithium-x64.h	(revision 9006)
+++ src/x64/lithium-x64.h	(working copy)
@@ -92,8 +92,7 @@
   V(DivI)                                       \
   V(DoubleToI)                                  \
   V(ElementsKind)                               \
-  V(ExternalArrayLength)                        \
-  V(FixedArrayLength)                           \
+  V(FixedArrayBaseLength)                       \
   V(FunctionLiteral)                            \
   V(GetCachedArrayIndex)                        \
   V(GlobalObject)                               \
@@ -913,28 +912,18 @@
 };
 
 
-class LExternalArrayLength: public LTemplateInstruction<1, 1, 0> {
+class LFixedArrayBaseLength: public LTemplateInstruction<1, 1, 0> {
  public:
-  explicit LExternalArrayLength(LOperand* value) {
+  explicit LFixedArrayBaseLength(LOperand* value) {
     inputs_[0] = value;
   }
 
-  DECLARE_CONCRETE_INSTRUCTION(ExternalArrayLength, "external-array-length")
-  DECLARE_HYDROGEN_ACCESSOR(ExternalArrayLength)
+  DECLARE_CONCRETE_INSTRUCTION(FixedArrayBaseLength,
+                               "fixed-array-base-length")
+  DECLARE_HYDROGEN_ACCESSOR(FixedArrayBaseLength)
 };
 
 
-class LFixedArrayLength: public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LFixedArrayLength(LOperand* value) {
-    inputs_[0] = value;
-  }
-
-  DECLARE_CONCRETE_INSTRUCTION(FixedArrayLength, "fixed-array-length")
-  DECLARE_HYDROGEN_ACCESSOR(FixedArrayLength)
-};
-
-
 class LElementsKind: public LTemplateInstruction<1, 1, 0> {
  public:
   explicit LElementsKind(LOperand* value) {
@@ -2136,14 +2125,18 @@
   template<int I, int T>
       LInstruction* DefineFixedDouble(LTemplateInstruction<1, I, T>* instr,
                                       XMMRegister reg);
+  // Assigns an environment to an instruction.  An instruction which can
+  // deoptimize must have an environment.
   LInstruction* AssignEnvironment(LInstruction* instr);
+  // Assigns a pointer map to an instruction.  An instruction which can
+  // trigger a GC or a lazy deoptimization must have a pointer map.
   LInstruction* AssignPointerMap(LInstruction* instr);
 
   enum CanDeoptimize { CAN_DEOPTIMIZE_EAGERLY, CANNOT_DEOPTIMIZE_EAGERLY };
 
-  // By default we assume that instruction sequences generated for calls
-  // cannot deoptimize eagerly and we do not attach environment to this
-  // instruction.
+  // Marks a call for the register allocator.  Assigns a pointer map to
+  // support GC and lazy deoptimization.  Assigns an environment to support
+  // eager deoptimization if CAN_DEOPTIMIZE_EAGERLY.
   LInstruction* MarkAsCall(
       LInstruction* instr,
       HInstruction* hinstr,