sparse: fix debugrebuilddirsate when narrow extension is enabled dirstate wrapping in narrow extension converts the manifest object to a list. So let's assume we get a list of files in sparse extension. Differential Revision: https://phab.mercurial-scm.org/D5481

tests: show that debugrebuilddirstate is broken with narrow+sparse This adds a test to show that debugrebuildirstate is broken when both narrow and sparse extensions are enabled. Differential Revision: https://phab.mercurial-scm.org/D5480