Replace scalarlist optimizations and split external array loads into two IL instructions.

runtime/vm/deopt_instructions.cc

Index: runtime/vm/deopt_instructions.cc
===================================================================
--- runtime/vm/deopt_instructions.cc	(revision 20148)
+++ runtime/vm/deopt_instructions.cc	(working copy)
@@ -700,10 +700,10 @@
   } else if (from_loc.IsRegister()) {
     deopt_instr = new DeoptRegisterInstr(from_loc.reg());
   } else if (from_loc.IsFpuRegister()) {
-    if (from_loc.representation() == Location::kDouble) {
+    if (from_loc.representation() == kUnboxedDouble) {
       deopt_instr = new DeoptFpuRegisterInstr(from_loc.fpu_reg());
     } else {
-      ASSERT(from_loc.representation() == Location::kMint);
+      ASSERT(from_loc.representation() == kUnboxedMint);
       deopt_instr = new DeoptInt64FpuRegisterInstr(from_loc.fpu_reg());
     }
   } else if (from_loc.IsStackSlot()) {
@@ -715,10 +715,10 @@
     intptr_t from_index = (from_loc.stack_index() < 0) ?
         from_loc.stack_index() + num_args_ :
         from_loc.stack_index() + num_args_ - kFirstLocalSlotIndex + 1;
-    if (from_loc.representation() == Location::kDouble) {
+    if (from_loc.representation() == kUnboxedDouble) {
       deopt_instr = new DeoptDoubleStackSlotInstr(from_index);
     } else {
-      ASSERT(from_loc.representation() == Location::kMint);
+      ASSERT(from_loc.representation() == kUnboxedMint);
       deopt_instr = new DeoptInt64StackSlotInstr(from_index);
     }
   } else {