[turbofan] Canonicalize return sequence for JSFunctions.

src/compiler/arm64/code-generator-arm64.cc

 // Copyright 2014 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/compiler/code-generator.h"
 
 #include "src/arm64/macro-assembler-arm64.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 1135 matching lines @@
         __ Add(csp, csp, AlignedStackSlots(stack_slots) * kPointerSize);
       }
       // Restore registers.
       // TODO(dcarney): correct callee saved registers.
       __ PopCalleeSavedRegisters();
     }
     __ Mov(csp, fp);
     __ Pop(fp, lr);
     __ Ret();
   } else if (descriptor->IsJSFunctionCall() || needs_frame_) {
-    __ Mov(jssp, fp);
-    __ Pop(fp, lr);
-    int pop_count = descriptor->IsJSFunctionCall()
-                        ? static_cast<int>(descriptor->JSParameterCount())
-                        : 0;
-    __ Drop(pop_count);
-    __ Ret();
+    // Canonicalize JSFunction return sites for now.
+    if (return_label_.is_bound()) {
+      __ B(&return_label_);
+    } else {
+      __ Bind(&return_label_);
+      __ Mov(jssp, fp);
+      __ Pop(fp, lr);
+      int pop_count = descriptor->IsJSFunctionCall()
+                          ? static_cast<int>(descriptor->JSParameterCount())
+                          : 0;
+      __ Drop(pop_count);
+      __ Ret();
+    }
   } else {
     __ Ret();
   }
 }
 
 
 void CodeGenerator::AssembleMove(InstructionOperand* source,
                                  InstructionOperand* destination) {
   Arm64OperandConverter g(this, NULL);
   // Dispatch on the source and destination operand kinds.  Not all
@@ skipping 173 matching lines @@
       }
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8