Recognize List constructor and turn it into CreateArray ...

runtime/vm/stub_code_arm64.cc

Index: runtime/vm/stub_code_arm64.cc
===================================================================
--- runtime/vm/stub_code_arm64.cc	(revision 36136)
+++ runtime/vm/stub_code_arm64.cc	(working copy)
@@ -617,12 +617,17 @@
     // and is computed as:
     // RoundedAllocationSize((array_length * kwordSize) + sizeof(RawArray)).
     // Assert that length is a Smi.
+
+    // TODO(zra): Fix code below before enabling.
+    __ b(&slow_case);
     __ tsti(R2, kSmiTagMask);
     if (FLAG_use_slow_path) {
       __ b(&slow_case);
     } else {
       __ b(&slow_case, NE);
     }
+    __ cmp(R2, Operand(0));
+    __ b(&slow_case, LT);
     __ LoadFieldFromOffset(R8, CTX, Context::isolate_offset(), kNoPP);
     __ LoadFromOffset(R8, R8, Isolate::heap_offset(), kNoPP);
     __ LoadFromOffset(R8, R8, Heap::new_space_offset(), kNoPP);
@@ -638,7 +643,8 @@
     __ add(R3, R3, Operand(R2, LSL, 2));  // R2 is Smi.
     ASSERT(kSmiTagShift == 1);
     __ andi(R3, R3, ~(kObjectAlignment - 1));
-    __ add(R7, R3, Operand(R0));
+    __ adds(R7, R3, Operand(R0));
+    __ b(&slow_case, VS);
 
     // Check if the allocation fits into the remaining space.
     // R0: potential new object start.