This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This patch teaches LLDB about Mach-O filesets. Filsets are Mach-O files
that contain a bunch of other Mach-O files. Unlike universal binaries,
which have a different header, Filesets use load commands to describe
the different entries it contains.
Differential revision: https://reviews.llvm.org/D132433
