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

test/unittests/compiler/instruction-sequence-unittest.cc

Index: test/unittests/compiler/instruction-sequence-unittest.cc
diff --git a/test/unittests/compiler/instruction-sequence-unittest.cc b/test/unittests/compiler/instruction-sequence-unittest.cc
index abc53940efe4c45aafb228e10892bc8af992c29d..f659b07887fbcbf02e4ff400abb15030f3a7c3d1 100644
--- a/test/unittests/compiler/instruction-sequence-unittest.cc
+++ b/test/unittests/compiler/instruction-sequence-unittest.cc
@@ -109,7 +109,7 @@ Instruction* InstructionSequenceTest::EndBlock(BlockCompletion completion) {
     case kBlockEnd:
       break;
     case kFallThrough:
-      result = EmitFallThrough();
+      result = EmitJump();
       break;
     case kJump:
       CHECK(!block_returns_);
@@ -441,11 +441,20 @@ InstructionBlock* InstructionSequenceTest::NewBlock() {
 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_);