[test] make instruction sequence test emit cfgs more like the scheduler

test/unittests/compiler/instruction-sequence-unittest.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/base/utils/random-number-generator.h"
 #include "src/compiler/pipeline.h"
 #include "test/unittests/compiler/instruction-sequence-unittest.h"
 #include "test/unittests/test-utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
@@ skipping 91 matching lines @@
 Instruction* InstructionSequenceTest::EndBlock(BlockCompletion completion) {
   Instruction* result = nullptr;
   if (block_returns_) {
     CHECK(completion.type_ == kBlockEnd || completion.type_ == kFallThrough);
     completion.type_ = kBlockEnd;
   }
   switch (completion.type_) {
     case kBlockEnd:
       break;
     case kFallThrough:
-      result = EmitFallThrough();
+      result = EmitJump();
       break;
     case kJump:
       CHECK(!block_returns_);
       result = EmitJump();
       break;
     case kBranch:
       CHECK(!block_returns_);
       result = EmitBranch(completion.op_);
       break;
   }
@@ skipping 311 matching lines @@
   instruction_blocks_.push_back(instruction_block);
   current_block_ = instruction_block;
   sequence()->StartBlock(rpo);
   return instruction_block;
 }
 
 
 void InstructionSequenceTest::WireBlocks() {
   CHECK(!current_block());
   CHECK(instruction_blocks_.size() == completions_.size());
+  CHECK(loop_blocks_.empty());
+  // Wire in end block to look like a scheduler produced cfg.
+  auto end_block = NewBlock();
+  current_block_ = nullptr;
+  sequence()->EndBlock(end_block->rpo_number());
   size_t offset = 0;
   for (const auto& completion : completions_) {
     switch (completion.type_) {
-      case kBlockEnd:
+      case kBlockEnd: {
+        auto block = instruction_blocks_[offset];
+        block->successors().push_back(end_block->rpo_number());
+        end_block->predecessors().push_back(block->rpo_number());
         break;
+      }
       case kFallThrough:  // Fallthrough.
       case kJump:
         WireBlock(offset, completion.offset_0_);
         break;
       case kBranch:
         WireBlock(offset, completion.offset_0_);
         WireBlock(offset, completion.offset_1_);
         break;
     }
     ++offset;
@@ skipping 24 matching lines @@
 
 
 Instruction* InstructionSequenceTest::AddInstruction(Instruction* instruction) {
   sequence()->AddInstruction(instruction);
   return instruction;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8