[LLDB] Accept connections via both "listen://" and "tcp://"

Summary:
A previous [internal patch](https://www.internalfb.com/phabricator/commit/OMEXTLLVMPROJECT/76d297cbe06b80e8d71cb96daa3245ef2f65cf76) removed the support of the "listen://" protocol, and changed to "tcp://". The latter is required to support [RL use cases](https://fburl.com/code/bql6tq63).

However, the removal of "listen://" cause the upstream lldb-dap VS Code extension to not work, because [they rely on this protocol](https://github.com/llvm/llvm-project/blob/7162f191b8ce68dddb60e3f129f786afb08b2bbb/lldb/tools/lldb-dap/src-ts/lldb-dap-server.ts#L29).

This diff changes it so that it supports both.

Test Plan:
The lldb-dap supports both "listen://" and "tcp://"

```
royshi-mac-office ~/llvm-sand/gen/usr/bin % ./lldb-dap --connection listen://localhost:0
Listening for: connection://[::1]:51376, connection://[127.0.0.1]:51376
^C%

royshi-mac-office ~/llvm-sand/gen/usr/bin % ./lldb-dap --connection tcp://localhost:0
Listening for: connection://[::1]:51382, connection://[127.0.0.1]:51382
^C%

royshi-mac-office ~/llvm-sand/gen/usr/bin % ./lldb-dap --version
lldb-dap: Facebook LLVM version 15.71.0
  DEBUG build with assertions.
liblldb: Meta lldb version 15.71.0.

See https://fburl.com/lldb_updates for a list of updates.

 (http://git.edge.x2p.facebook.net/repos/git/rw/osmeta/external/llvm-project revision 1f0e2624ad1fc58e65c7289014c2850ea770bab3)
  clang revision 1f0e2624ad1fc58e65c7289014c2850ea770bab3
  llvm revision 1f0e2624ad1fc58e65c7289014c2850ea770bab3

royshi-mac-office ~/llvm-sand/external/llvm-project % gitlog
* 1f0e2624ad1f - (HEAD) [LLDB] Accept connections via both "listen://" and "tcp://" (44 minutes ago) <Roy Shi>
* 9360e52 - (origin/toolchain/llvm-sand/next-main, m/toolchain/llvm-sand-next) Implement parallel module loading for ModuleList DYLD (2 hours ago) <George Hu>
```

Rollback Plan:

Reviewers: alexandreperez, peix, wanyi, #lldb_team

Reviewed By: alexandreperez

Subscribers: #lldb_team

Differential Revision: https://phabricator.intern.facebook.com/D79139845

Author: royitaqi

lldb/source/Host/common/Socket.cpp

@@ -498,8 +498,8 @@ std::optional<Socket::ProtocolModePair>
 Socket::GetProtocolAndMode(llvm::StringRef scheme) {
   // Keep in sync with ConnectionFileDescriptor::Connect.
   return llvm::StringSwitch<std::optional<ProtocolModePair>>(scheme)
-      .Case("tcp", ProtocolModePair{SocketProtocol::ProtocolTcp,
-                                    SocketMode::ModeAccept})
+      .Cases("listen", "tcp", ProtocolModePair{SocketProtocol::ProtocolTcp,
+                                               SocketMode::ModeAccept})
       .Cases("unix", "unix-accept",
              ProtocolModePair{SocketProtocol::ProtocolUnixDomain,
                               SocketMode::ModeAccept})