[X87] [Ignition] Fix V8 x87 code generation bugs when Ingition was enabled.

src/crankshaft/x87/lithium-codegen-x87.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_X87
 
 #include "src/crankshaft/x87/lithium-codegen-x87.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 183 matching lines @@
 }
 
 
 void LCodeGen::GenerateOsrPrologue() {
   // Generate the OSR entry prologue at the first unknown OSR value, or if there
   // are none, at the OSR entrypoint instruction.
   if (osr_pc_offset_ >= 0) return;
 
   osr_pc_offset_ = masm()->pc_offset();
 
+  // Interpreter is the first tier compiler now. It will run the code generated
+  // by TurboFan compiler which will always put "1" on x87 FPU stack.
+  // This behavior will affect crankshaft's x87 FPU stack depth check under
+  // debug mode.
+  // Need to reset the FPU stack here for this scenario.
+  __ fninit();
+
   // Adjust the frame size, subsuming the unoptimized frame into the
   // optimized frame.
   int slots = GetStackSlotCount() - graph()->osr()->UnoptimizedFrameSlots();
   DCHECK(slots >= 0);
   __ sub(esp, Immediate(slots * kPointerSize));
 }
 
 
 void LCodeGen::GenerateBodyInstructionPre(LInstruction* instr) {
   if (instr->IsCall()) {
@@ skipping 5619 matching lines @@
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87