[turbofan] First step towards sanitizing for-in and making it optimizable.

src/arm64/full-codegen-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 1236 matching lines @@
 
   // For proxies, no filtering is done.
   // TODO(rossberg): What if only a prototype is a proxy? Not specified yet.
   STATIC_ASSERT(kSmiTag == 0);
   __ Cbz(x2, &update_each);
 
   // Convert the entry to a string or (smi) 0 if it isn't a property
   // any more. If the property has been removed while iterating, we
   // just skip it.
   __ Push(x1, x3);
-  __ InvokeBuiltin(Builtins::FILTER_KEY, CALL_FUNCTION);
+  __ CallRuntime(Runtime::kForInFilter, 2);
   PrepareForBailoutForId(stmt->FilterId(), TOS_REG);
   __ Mov(x3, x0);
-  __ Cbz(x0, loop_statement.continue_label());
+  __ JumpIfRoot(x0, Heap::kUndefinedValueRootIndex,
+                loop_statement.continue_label());
 
   // Update the 'each' property or variable from the possibly filtered
   // entry in register x3.
   __ Bind(&update_each);
   __ Mov(result_register(), x3);
   // Perform the assignment as if via '='.
   { EffectContext context(this);
     EmitAssignment(stmt->each(), stmt->EachFeedbackSlot());
     PrepareForBailoutForId(stmt->AssignmentId(), NO_REGISTERS);
   }
@@ skipping 4265 matching lines @@
     }
   }
 
   return INTERRUPT;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64