patch 8.1.0184: not easy to figure out the window layout

Problem:    Not easy to figure out the window layout.
Solution:   Add "wincol" and "winrow" to what getwininfo() returns.

runtime/doc/eval.txt

@@ -4994,8 +4994,10 @@ getwininfo([{winid}])					*getwininfo()*
			variables	a reference to the dictionary with
					window-local variables
			width		window width
			wincol		leftmost screen column of the window
			winid		|window-ID|
			winnr		window number
			winrow		topmost screen column of the window

		To obtain all window-local variables use: >
			gettabwinvar({tabnr}, {winnr}, '&')

src/evalfunc.c

@@ -5648,10 +5648,12 @@ get_win_info(win_T *wp, short tpnr, short winnr)
    dict_add_number(dict, "winnr", winnr);
    dict_add_number(dict, "winid", wp->w_id);
    dict_add_number(dict, "height", wp->w_height);
    dict_add_number(dict, "winrow", wp->w_winrow);
#ifdef FEAT_MENU
    dict_add_number(dict, "winbar", wp->w_winbar_height);
#endif
    dict_add_number(dict, "width", wp->w_width);
    dict_add_number(dict, "wincol", wp->w_wincol);
    dict_add_number(dict, "bufnr", wp->w_buffer->b_fnum);

#ifdef FEAT_TERMINAL

src/testdir/test_bufwintabinfo.vim

@@ -46,17 +46,34 @@ function Test_getbufwintabinfo()
    let w2_id = win_getid()
    tabnew | let w3_id = win_getid()
    new | let w4_id = win_getid()
    new | let w5_id = win_getid()
    vert new | let w5_id = win_getid()
    call setwinvar(0, 'signal', 'green')
    tabfirst
    let winlist = getwininfo()
    call assert_equal(5, len(winlist))
    call assert_equal(winwidth(1), winlist[0].width)
    call assert_equal(0, winlist[0].wincol)
    call assert_equal(1, winlist[0].winrow)  " tabline adds one

    call assert_equal(winbufnr(2), winlist[1].bufnr)
    call assert_equal(winheight(2), winlist[1].height)
    call assert_equal(0, winlist[1].wincol)
    call assert_equal(winheight(1) + 2, winlist[1].winrow)

    call assert_equal(1, winlist[2].winnr)
    call assert_equal(1, winlist[2].winrow)
    call assert_equal(0, winlist[2].wincol)

    call assert_equal(winlist[2].width + 1, winlist[3].wincol)
    call assert_equal(0, winlist[4].wincol)

    call assert_equal(1, winlist[0].tabnr)
    call assert_equal(1, winlist[1].tabnr)
    call assert_equal(2, winlist[2].tabnr)
    call assert_equal(2, winlist[3].tabnr)
    call assert_equal(2, winlist[4].tabnr)

    call assert_equal('green', winlist[2].variables.signal)
    call assert_equal(winwidth(1), winlist[0].width)
    call assert_equal(w4_id, winlist[3].winid)
    let winfo = getwininfo(w5_id)[0]
    call assert_equal(2, winfo.tabnr)

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =

static int included_patches[] =
{   /* Add new patch number below this line */
/**/
    184,
/**/
    183,
/**/