[lldb] Eliminate dead code (NFC)

Author: adrian-prantl

lldb/source/DataFormatters/FormatterBytecode.cpp

@@ -392,8 +392,6 @@ llvm::Error Interpret(std::vector<ControlStackElement> &control,
  int64_t x = data.Pop<int64_t>(); \
  if (y > 64) \
  return error("shift out of bounds"); \
- if (y < 0) \
- return error("shift out of bounds"); \
  data.Push(x OP y); \
  } else \
  return error("unsupported data types"); \