[LLDB] Serve unknown type symbols through `qSymbol` for non-MachO targets (#200134)

I am working with a binary where some symbols are generated from linker
scripts. They end up identified as `eSymbolInvalid` when loaded in LLDB.
OpenOCD can try to fetch them.

Some might even be hard-coded data, not going through an address in the
binary (explaining the presence of the check and raw value
return).

Testing it showed that **GDB returns them despite them not being proper
addresses**.
These can also be generated by C++ static constexpr, such values could
be accessed by a qSymbol query.

358cf1ea302eb introduced a divergence between GDB and LLDB where LLDB
does not serve symbols of unknown type through GDB protocol command
`qSymbol`. Per commit description, this is an expected behavior on
MachO-based platforms, but it is not on ELF-based platforms, where LLDB
should follow GDB. The changes introduced by said commit are now gated
behind an architecture check.

GitOrigin-RevId: 04c9cf4743fc62ca555f270f3621b324e2472767