[lldb] Improve corefile saving ergonomics

This patch improves the way the user can save the process state into a
corefile by adding completion handler that would provide tab completion
for the corefile path and also resolves the corefile path to expand
relative path.

Differential Revision: https://reviews.llvm.org/D152842

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>

lldb/source/API/SBProcess.cpp

@@ -1183,6 +1183,7 @@ lldb::SBError SBProcess::SaveCore(const char *file_name,
   }
 
   FileSpec core_file(file_name);
+  FileSystem::Instance().Resolve(core_file);
   error.ref() = PluginManager::SaveCore(process_sp, core_file, core_style,
                                         flavor);