[turbofan] Frame deconstruction self-validation.

src/compiler/code-generator.cc

 // Copyright 2013 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/compiler/code-generator.h"
 
 #include "src/address-map.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/pipeline.h"
@@ skipping 294 matching lines @@
 void CodeGenerator::AssembleBlock(const InstructionBlock* block) {
   for (int i = block->code_start(); i < block->code_end(); ++i) {
     Instruction* instr = code()->InstructionAt(i);
     AssembleInstruction(instr, block);
   }
 }
 
 void CodeGenerator::AssembleInstruction(Instruction* instr,
                                         const InstructionBlock* block) {
   AssembleGaps(instr);
+  DCHECK_IMPLIES(
+      block->must_deconstruct_frame(),
+      instr != code()->InstructionAt(block->last_instruction_index()) ||
+          instr->IsRet() || instr->IsJump());
   if (instr->IsJump() && block->must_deconstruct_frame()) {
     AssembleDeconstructFrame();
   }
   AssembleSourcePosition(instr);
   // Assemble architecture-specific code for the instruction.
   AssembleArchInstruction(instr);
 
   FlagsMode mode = FlagsModeField::decode(instr->opcode());
   FlagsCondition condition = FlagsConditionField::decode(instr->opcode());
   switch (mode) {
@@ skipping 473 matching lines @@
     : frame_(gen->frame()), masm_(gen->masm()), next_(gen->ools_) {
   gen->ools_ = this;
 }
 
 
 OutOfLineCode::~OutOfLineCode() {}
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8