[lldb][Windows] Always call SetExecutableModule on debugger connected

[lldb][Windows] Always call SetExecutableModule on debugger connected

In `ProcessWindows::OnDebuggerConnected` (triggered from
`CREATE_PROCESS_DEBUG_EVENT`), we should always call
`Target::SetExecutableModule` regardless of whether LLDB has already
preloaded the executable modules. `SetExecutableModule` has the side
effect of clearing the module list of the Target, which help make sure
that module #0 is the executable module and the rest of the modules are
listed according to the DLL load order in the process (technically this
has no real consequences but it seems to make more sense anyway.) It
also fixes an issue where the modules preloaded by LLDB will be
duplicated when the debuggee process actually loads the DLL.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D134636