Add the ability to override the disassembly CPU and CPU features through
a target setting (`target.disassembly-cpu` and
`target.disassembly-features`) and a `disassemble` command option
(`--cpu` and `--features`).

This is especially relevant for architectures like RISC-V which relies
heavily on CPU extensions.

The majority of this patch is plumbing the options through. I recommend
looking at DisassemblerLLVMC and the test for the observable change in
behavior.

This is another step towards supporting DWARF5 checksums and inline
source code in LLDB. This is a reland of #85468 but without the
functional change of storing the support file from the line table (yet).

Reverts llvm/llvm-project#85468 because @slackito reports this broke
stepping in one of their tests [1] and this patch was meant to be NFC.

[1]
https://github.com/llvm/llvm-project/commit/d5a277d309e92b1d3e493da6036cffdf815105b1#commitcomment-139991120

This is another step towards supporting DWARF5 checksums and inline
source code in LLDB.

Prior to this patch, each core file plugin (ObjectFileMachO.cpp and
ObjectFileMinindump.cpp) would calculate the address ranges to save in
different ways. This patch adds a new function to Process.h/.cpp:

```
Status Process::CalculateCoreFileSaveRanges(lldb::SaveCoreStyle core_style, CoreFileMemoryRanges &ranges);
```

The patch updates the ObjectFileMachO::SaveCore(...) and
ObjectFileMinindump::SaveCore(...) to use same code. This will allow
core files to be consistent with the lldb::SaveCoreStyle across
different core file creators and will allow us to add new core file
saving features that do more complex things in future patches.

This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to clean up the "using" declarations, #include
"llvm/ADT/Optional.h", etc.

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 adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
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

Many files are from language servers.

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

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 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