AK: Make LEB128 capable of reading into any type

And not just ssize_t/size_t.
This is useful in cases where the output size is supposed to be larger
than size_t.

AK/LEB128.h

@@ -12,8 +12,8 @@
 namespace AK {
 
 struct LEB128 {
- template<typename StreamT>
- static bool read_unsigned(StreamT& stream, size_t& result)
+ template<typename StreamT, typename ValueType = size_t>
+ static bool read_unsigned(StreamT& stream, ValueType& result)
  {
  [[maybe_unused]] size_t backup_offset = 0;
  if constexpr (requires { stream.offset(); })
@@ -35,7 +35,7 @@ struct LEB128 {
  if (input_stream.has_any_error())
  return false;
 
- result = (result) | (static_cast<size_t>(byte & ~(1 << 7)) << (num_bytes * 7));
+ result = (result) | (static_cast<ValueType>(byte & ~(1 << 7)) << (num_bytes * 7));
  if (!(byte & (1 << 7)))
  break;
  ++num_bytes;
@@ -44,9 +44,10 @@ struct LEB128 {
  return true;
  }
 
- template<typename StreamT>
- static bool read_signed(StreamT& stream, ssize_t& result)
+ template<typename StreamT, typename ValueType = ssize_t>
+ static bool read_signed(StreamT& stream, ValueType& result)
  {
+ using UValueType = MakeUnsigned<ValueType>;
  [[maybe_unused]] size_t backup_offset = 0;
  if constexpr (requires { stream.offset(); })
  backup_offset = stream.offset();
@@ -67,13 +68,13 @@ struct LEB128 {
  input_stream >> byte;
  if (input_stream.has_any_error())
  return false;
- result = (result) | (static_cast<size_t>(byte & ~(1 << 7)) << (num_bytes * 7));
+ result = (result) | (static_cast<UValueType>(byte & ~(1 << 7)) << (num_bytes * 7));
  ++num_bytes;
  } while (byte & (1 << 7));
 
- if (num_bytes * 7 < sizeof(size_t) * 4 && (byte & 0x40)) {
+ if (num_bytes * 7 < sizeof(UValueType) * 4 && (byte & 0x40)) {
  // sign extend
- result |= ((size_t)(-1) << (num_bytes * 7));
+ result |= ((UValueType)(-1) << (num_bytes * 7));
  }
 
  return true;