d6fcaef281
When reading a value as a scalar, the type size is required. It's returned as a `std::optional`. This optional isn't checked for scalar values, where it is unconditionally accessed. This came up in the [Shell/Process/Windows/msstl_smoke.cpp](4e10b62442/lldb/test/Shell/Process/Windows/msstl_smoke.cpp) test. There, LLDB breaks at the function entry, so all locals aren't initialized yet. Most values will contain garbage. The [`std::list` synthetic provider](4e10b62442/lldb/source/Plugins/Language/CPlusPlus/GenericList.cpp (L517)) tries to read the value using `GetData`. However, in [`ValueObject::GetData`](4e10b62442/lldb/source/ValueObject/ValueObject.cpp (L766)), [`ValueObjectChild::UpdateValue`](88c993fbc5/lldb/source/ValueObject/ValueObjectChild.cpp (L102)) fails because the parent already failed to read its data, so `m_value` won't have a compiler type, thus the size can't be read.