[turbofan]: Support using push instructions for setting up tail call parameters

src/compiler/code-generator.cc

Index: src/compiler/code-generator.cc
diff --git a/src/compiler/code-generator.cc b/src/compiler/code-generator.cc
index f3886593b14b5fadd4ccc27be037f88222ce42f1..968abd2e7c6ef05b8bd0fe2876d90bc764b27d49 100644
--- a/src/compiler/code-generator.cc
+++ b/src/compiler/code-generator.cc
@@ -417,8 +417,18 @@ void CodeGenerator::AssembleSourcePosition(Instruction* instr) {
   }
 }
 
+bool CodeGenerator::GetSlotAboveSPAfterGap(Instruction* instr, int* slot) {
+  if (instr->IsTailCall()) {
+    InstructionOperandConverter g(this, instr);
+    *slot = g.InputInt32(instr->InputCount() - 1);
+    return true;
+  } else {
+    return false;
+  }
+}
 
 void CodeGenerator::AssembleGaps(Instruction* instr) {
+  AssemblePreGaps(instr);
   for (int i = Instruction::FIRST_GAP_POSITION;
        i <= Instruction::LAST_GAP_POSITION; i++) {
     Instruction::GapPosition inner_pos =
@@ -426,6 +436,7 @@ void CodeGenerator::AssembleGaps(Instruction* instr) {
     ParallelMove* move = instr->GetParallelMove(inner_pos);
     if (move != nullptr) resolver()->Resolve(move);
   }
+  AssemblePostGaps(instr);
 }
 
 
@@ -799,18 +810,6 @@ DeoptimizationExit* CodeGenerator::AddDeoptimizationExit(
   return exit;
 }
 
-int CodeGenerator::TailCallFrameStackSlotDelta(int stack_param_delta) {
-  // Leave the PC on the stack on platforms that have that as part of their ABI
-  int pc_slots = V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK ? 1 : 0;
-  int sp_slot_delta = frame_access_state()->has_frame()
-                          ? (frame()->GetTotalFrameSlotCount() - pc_slots)
-                          : 0;
-  // Discard only slots that won't be used by new parameters.
-  sp_slot_delta += stack_param_delta;
-  return sp_slot_delta;
-}
-
-
 OutOfLineCode::OutOfLineCode(CodeGenerator* gen)
     : frame_(gen->frame()), masm_(gen->masm()), next_(gen->ools_) {
   gen->ools_ = this;