Save a few register moves in function prolog on arm64 by using the same pattern

runtime/vm/flow_graph_compiler_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 962 matching lines @@
 }
 
 
 void FlowGraphCompiler::EmitFrameEntry() {
   const Function& function = parsed_function().function();
   Register new_pp = kNoRegister;
   if (CanOptimizeFunction() &&
       function.IsOptimizable() &&
       (!is_optimizing() || may_reoptimize())) {
     const Register function_reg = R6;
-    const Register saved_pp = R7;
     new_pp = R13;
     // The pool pointer is not setup before entering the Dart frame.
-    // Preserve PP of caller.
-    __ mov(saved_pp, PP);
-
     // Temporarily setup pool pointer for this dart function.
-    __ LoadPoolPointer();
+    __ LoadPoolPointer(new_pp);
 
     // Load function object using the callee's pool pointer.
-    __ LoadObject(function_reg, function);
-    // Preserve new PP and restore PP of caller.
-    __ mov(new_pp, PP);
-    __ mov(PP, saved_pp);
-    __ set_constant_pool_allowed(false);
+    __ LoadFunctionFromCalleePool(function_reg, function, new_pp);
 
     // Patch point is after the eventually inlined function object.
     entry_patch_pc_offset_ = assembler()->CodeSize();
 
     __ LoadFieldFromOffset(
         R7, function_reg, Function::usage_counter_offset(), kWord);
     // Reoptimization of an optimized function is triggered by counting in
     // IC stubs, but not at the entry of the function.
     if (!is_optimizing()) {
       __ add(R7, R7, Operand(1));
@@ skipping 836 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   __ PopDouble(reg);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64