Implement inlined version of binary arithmetic operations for doubles.

runtime/vm/flow_graph_compiler_x64.h

Index: runtime/vm/flow_graph_compiler_x64.h
diff --git a/runtime/vm/flow_graph_compiler_x64.h b/runtime/vm/flow_graph_compiler_x64.h
index 65231026897b6daf0306bc4864fdb0a9076b6492..3a0d45d26ee1a55202ba390223540aa86e02dca9 100644
--- a/runtime/vm/flow_graph_compiler_x64.h
+++ b/runtime/vm/flow_graph_compiler_x64.h
@@ -38,6 +38,12 @@ class FlowGraphCompiler : public FlowGraphCompilerShared {
                            intptr_t try_index,
                            const RuntimeEntry& entry);
 
+  // Infrastructure copied from class CodeGenerator.
+  void GenerateCall(intptr_t token_index,
+                    intptr_t try_index,
+                    const ExternalLabel* label,
+                    PcDescriptors::Kind kind);
+
  private:
   friend class DeoptimizationStub;
 
@@ -71,12 +77,6 @@ class FlowGraphCompiler : public FlowGraphCompilerShared {
                                   const Array& arguments_descriptor,
                                   intptr_t argument_count);
 
-  // Infrastructure copied from class CodeGenerator.
-  void GenerateCall(intptr_t token_index,
-                    intptr_t try_index,
-                    const ExternalLabel* label,
-                    PcDescriptors::Kind kind);
-
   // Type checking helper methods.
   virtual void CheckClassIds(Register class_id_reg,
                              const GrowableArray<intptr_t>& class_ids,