patch 9.0.1397: highlight for popupmenu kind and extra cannot be set

Problem:    Highlight for popupmenu kind and extra cannot be set.
Solution:   Add PmenuKind, PmenuKindSel, PmenuExtra and PmenuExtraSel
            highlight groups and use them. (Gianmaria Bajo, closes #12114)
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 4f0ac45..799e05d 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -4198,6 +4198,8 @@
 				     T:DiffText,>:SignColumn,-:Conceal,
 				     B:SpellBad,P:SpellCap,R:SpellRare,
 				     L:SpellLocal,+:Pmenu,=:PmenuSel,
+				     [:PmenuKind,]:PmenuKindSel,
+				     {:PmenuExtra,}:PmenuExtraSel,
 				     x:PmenuSbar,X:PmenuThumb,*:TabLine,
 				     #:TabLineSel,_:TabLineFill,!:CursorColumn,
 				     .:CursorLine,o:ColorColumn,q:QuickFixLine,
@@ -4254,6 +4256,10 @@
 	|hl-SpellLocal|	 L  word from other region |spell|
 	|hl-Pmenu|	 +  popup menu normal line
 	|hl-PmenuSel|	 =  popup menu selected line
+	|hl-PmenuKind|	 [  popup menu "kind" normal line
+	|hl-PmenuKindSel|  ]  popup menu "kind" selected line
+	|hl-PmenuExtra|	 {  popup menu "kind" normal line
+	|hl-PmenuExtraSel| }  popup menu "kind" selected line
 	|hl-PmenuSbar|	 x  popup menu scrollbar
 	|hl-PmenuThumb|	 X  popup menu scrollbar thumb
 
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index d624e4d..93c56a2 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -5452,6 +5452,14 @@
 Pmenu		Popup menu: Normal item.
 							*hl-PmenuSel*
 PmenuSel	Popup menu: Selected item.
+							*hl-PmenuKind*
+PmenuKind	Popup menu: Normal item "kind".
+							*hl-PmenuKindSel*
+PmenuKindSel	Popup menu: Selected item "kind".
+							*hl-PmenuExtra*
+PmenuExtra	Popup menu: Normal item "extra text".
+							*hl-PmenuExtraSel*
+PmenuExtraSel	Popup menu: Selected item "extra text".
 							*hl-PmenuSbar*
 PmenuSbar	Popup menu: Scrollbar.
 							*hl-PmenuThumb*