[lldb/NativePDB] Don't create parentless blocks (#117581)

In case of an error GetBlock would return a reference to a Block without
adding it to a parent. This doesn't seem like a good idea, and none of
the other plugins do that.

This patch fixes that by propagating errors (well, null pointers...) up
the stack.

I don't know of any specific problem that this solves, but given that
this occurs only when something goes very wrong (e.g. a corrupted PDB
file), it's quite possible noone has run into this situation, so we
can't say the code is correct either. It also gets in the way of a
refactor I'm contemplating.

0 files changed, 0 insertions, 0 deletions