[interpreter] Reduce size of OSR nesting level field.

src/interpreter/interpreter-assembler.cc

Index: src/interpreter/interpreter-assembler.cc
diff --git a/src/interpreter/interpreter-assembler.cc b/src/interpreter/interpreter-assembler.cc
index 03d7a542be148b424bfaa560091212edd30b2658..42501a1add63f550b6f2b6362e6a388cbcdeb96c 100644
--- a/src/interpreter/interpreter-assembler.cc
+++ b/src/interpreter/interpreter-assembler.cc
@@ -848,7 +848,7 @@ Node* InterpreterAssembler::StackCheckTriggeredInterrupt() {
 Node* InterpreterAssembler::LoadOSRNestingLevel() {
   Node* offset =
       IntPtrConstant(BytecodeArray::kOSRNestingLevelOffset - kHeapObjectTag);
-  return Load(MachineType::Int32(), BytecodeArrayTaggedPointer(), offset);
+  return Load(MachineType::Int8(), BytecodeArrayTaggedPointer(), offset);
 }
 
 void InterpreterAssembler::Abort(BailoutReason bailout_reason) {