[turbofan] Remove Instruction::IsControl() and Instruction::MarkAsControl()

src/compiler/instruction.cc

Index: src/compiler/instruction.cc
diff --git a/src/compiler/instruction.cc b/src/compiler/instruction.cc
index 86f00f3a0af5799ad99291143341c70b4b6cf4fc..8446a0dcedf5358b5571cb6f1929e8a716c71894 100644
--- a/src/compiler/instruction.cc
+++ b/src/compiler/instruction.cc
@@ -109,8 +109,7 @@ MoveOperands* ParallelMove::PrepareInsertAfter(MoveOperands* move) const {
 Instruction::Instruction(InstructionCode opcode)
     : opcode_(opcode),
       bit_field_(OutputCountField::encode(0) | InputCountField::encode(0) |
-                 TempCountField::encode(0) | IsCallField::encode(false) |
-                 IsControlField::encode(false)),
+                 TempCountField::encode(0) | IsCallField::encode(false)),
       pointer_map_(NULL) {}
 
 
@@ -122,7 +121,7 @@ Instruction::Instruction(InstructionCode opcode, size_t output_count,
       bit_field_(OutputCountField::encode(output_count) |
                  InputCountField::encode(input_count) |
                  TempCountField::encode(temp_count) |
-                 IsCallField::encode(false) | IsControlField::encode(false)),
+                 IsCallField::encode(false)),
       pointer_map_(NULL) {
   size_t offset = 0;
   for (size_t i = 0; i < output_count; ++i) {