[S32-str/substr] Remove meaningless StrLen/*-1 tests, and fudge broken p() tests for Niecza
[S32-str/substr] Remove meaningless StrLen/*-1 tests, and fudge broken p() tests for Niecza

cygx/roast,bitrauser/roast,skids/roast,b2gills/roast,dankogai/roast,bitrauser/roast,zostay/roast,dankogai/roast,dogbert17/roast,niner/roast,laben/roast,dankogai/roast,dogbert17/roast,laben/roast,zostay/roast,perl6/roast,skids/roast,skids/roast,niner/roast,laben/roast,b2gills/roast,cygx/roast,zostay/roast,b2gills/roast,niner/roast,cygx/roast