Add modules downloaded by ModuleCache to the global ModuleList

[tberghammer]

Summary

Add modules downloaded by ModuleCache to the global ModuleList

Adding the modules to the global module list eliminate issues in the
case when a module is unloaded from the target but some object (e.g.
breakpoint) still referencing them with weak pointers. It also speeds
up the case when we load, unload, load the same shared library because
the global module cache will keep the parsed debug info around between
the 2 load (this scenario happens for some code on android).

[ovyalov]

LGTM

source/Utility/ModuleCache.cpp

 //===--------------------- ModuleCache.cpp ----------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "ModuleCache.h"
 
 #include "lldb/Core/Log.h"
 #include "lldb/Core/Module.h"
+#include "lldb/Core/ModuleList.h"
 #include "lldb/Core/ModuleSpec.h"
 #include "lldb/Host/File.h"
 #include "lldb/Host/FileSystem.h"
 #include "lldb/Host/LockFile.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/FileUtilities.h"
 
 #include <assert.h>
ModuleCache::Get (const FileSpec &root_dir_spec,
     const auto module_file_path = JoinPath (module_spec_dir, module_spec.GetFileSpec ().GetFilename ().AsCString ());
 
     if (!module_file_path.Exists ())
         return Error ("Module %s not found", module_file_path.GetPath ().c_str ());
     if (module_file_path.GetByteSize () != module_spec.GetObjectSize ())
         return Error ("Module %s has invalid file size", module_file_path.GetPath ().c_str ());
 
     // We may have already cached module but downloaded from an another host - in this case let's create a link to it.
-    const auto error = CreateHostSysRootModuleLink(root_dir_spec, hostname, module_spec.GetFileSpec(), module_file_path, false);
+    auto error = CreateHostSysRootModuleLink(root_dir_spec, hostname, module_spec.GetFileSpec(), module_file_path, false);
     if (error.Fail ())
         return Error ("Failed to create link to %s: %s", module_file_path.GetPath().c_str(), error.AsCString());
 
     auto cached_module_spec (module_spec);
     cached_module_spec.GetUUID ().Clear ();  // Clear UUID since it may contain md5 content hash instead of real UUID.
     cached_module_spec.GetFileSpec () = module_file_path;
     cached_module_spec.GetPlatformFileSpec () = module_spec.GetFileSpec ();
-    cached_module_sp.reset (new Module (cached_module_spec));
+    
+    error = ModuleList::GetSharedModule(cached_module_spec,
+                                        cached_module_sp,
+                                        nullptr,
+                                        nullptr,
+                                        did_create_ptr,
+                                        false);
+    if (error.Fail())
+        return error;
 
     FileSpec symfile_spec = GetSymbolFileSpec(cached_module_sp->GetFileSpec ());
     if (symfile_spec.Exists ())
         cached_module_sp->SetSymbolFileFileSpec (symfile_spec);
 
-    if (did_create_ptr)
-        *did_create_ptr = true;
-
     m_loaded_modules.insert (std::make_pair (module_spec.GetUUID ().GetAsString (), cached_module_sp));
 
     return Error ();
 }
 
 Error
 ModuleCache::GetAndPut (const FileSpec &root_dir_spec,
                         const char *hostname,