[ignition] Properly track validity of the bytecode array.

The debugger replaces the bytecode array when breakpoints are set
by walking the stack and mutating the dedicated stack slots for the
bytecode arrays. This means that Ignition has to properly reload the
bytecode array after calls, which works for a single call inside a
bytecode handler, but fails if there are multiple calls.

R=rmcilroy@chromium.org

Change-Id: Ia7744edc91490014d77ad9ad17a328cab5f8530f
Reviewed-on: https://chromium-review.googlesource.com/603410Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47190}

src/interpreter/interpreter-assembler.cc

@@ -33,6 +33,7 @@ InterpreterAssembler::InterpreterAssembler(CodeAssemblerState* state,
       bytecode_offset_(this, MachineType::PointerRepresentation()),
       interpreted_frame_pointer_(this, MachineType::PointerRepresentation()),
       bytecode_array_(this, MachineRepresentation::kTagged),
+      bytecode_array_valid_(true),
       dispatch_table_(this, MachineType::PointerRepresentation()),
       accumulator_(this, MachineRepresentation::kTagged),
       accumulator_use_(AccumulatorUse::kNone),
@@ -180,10 +181,9 @@ Node* InterpreterAssembler::BytecodeOffset() {
 Node* InterpreterAssembler::BytecodeArrayTaggedPointer() {
   // Force a re-load of the bytecode array after every call in case the debugger
   // has been activated.
-  if (made_call_ &&
-      (bytecode_array_.value() ==
-       Parameter(InterpreterDispatchDescriptor::kBytecodeArray))) {
+  if (!bytecode_array_valid_) {
     bytecode_array_.Bind(LoadRegister(Register::bytecode_array()));
+    bytecode_array_valid_ = true;
   }
   return bytecode_array_.value();
 }
@@ -539,6 +539,7 @@ void InterpreterAssembler::CallPrologue() {
     DCHECK(stack_pointer_before_call_ == nullptr);
     stack_pointer_before_call_ = LoadStackPointer();
   }
+  bytecode_array_valid_ = false;
   made_call_ = true;
 }
 

src/interpreter/interpreter-assembler.h

@@ -363,6 +363,7 @@ class V8_EXPORT_PRIVATE InterpreterAssembler : public CodeStubAssembler {
   CodeStubAssembler::Variable bytecode_offset_;
   CodeStubAssembler::Variable interpreted_frame_pointer_;
   CodeStubAssembler::Variable bytecode_array_;
+  bool bytecode_array_valid_;
   CodeStubAssembler::Variable dispatch_table_;
   CodeStubAssembler::Variable accumulator_;
   AccumulatorUse accumulator_use_;