Resubmit FileSystem changes.

This was originall reverted due to some test failures in
ModuleCache and TestCompDirSymlink.  These issues have all
been resolved and the code now passes all tests.

Differential Revision: https://reviews.llvm.org/D30698

llvm-svn: 297300

lldb/source/Core/ModuleList.cpp

@@ -26,6 +26,7 @@
 #include "lldb/Symbol/VariableList.h"
 #include "lldb/Utility/Log.h"
 
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Threading.h"
 
 using namespace lldb;
@@ -766,7 +767,8 @@ Error ModuleList::GetSharedModule(const ModuleSpec &module_spec,
       auto search_path_spec = module_search_paths_ptr->GetFileSpecAtIndex(idx);
       if (!search_path_spec.ResolvePath())
         continue;
-      if (!search_path_spec.Exists() || !search_path_spec.IsDirectory())
+      namespace fs = llvm::sys::fs;
+      if (!fs::is_directory(search_path_spec.GetPath()))
         continue;
       search_path_spec.AppendPathComponent(
           module_spec.GetFileSpec().GetFilename().AsCString());