Delete code for the now unused IL instruction NumberNegate.

runtime/vm/flow_graph_compiler_x64.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_FLOW_GRAPH_COMPILER_X64_H_
 #define VM_FLOW_GRAPH_COMPILER_X64_H_
 
 #ifndef VM_FLOW_GRAPH_COMPILER_H_
 #error Include flow_graph_compiler.h instead of flow_graph_compiler_x64.h.
 #endif
@@ skipping 98 matching lines @@
                             intptr_t checked_argument_count,
                             LocationSummary* locs);
 
   void GenerateStaticCall(intptr_t deopt_id,
                           intptr_t token_pos,
                           const Function& function,
                           intptr_t argument_count,
                           const Array& argument_names,
                           LocationSummary* locs);
 
-  void GenerateInlinedMathSqrt(Label* done);
-
   void GenerateNumberTypeCheck(Register kClassIdReg,
                                const AbstractType& type,
                                Label* is_instance_lbl,
                                Label* is_not_instance_lbl);
   void GenerateStringTypeCheck(Register kClassIdReg,
                                Label* is_instance_lbl,
                                Label* is_not_instance_lbl);
   void GenerateListTypeCheck(Register kClassIdReg,
                              Label* is_instance_lbl);
 
@@ skipping 190 matching lines @@
   // that should be used when deoptimizing we store it in this variable.
   // In future AddDeoptStub should be moved out of the instruction template.
   Environment* pending_deoptimization_env_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphCompiler);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_COMPILER_X64_H_