[css-position-4][editorial] 'fake stacking context' -> 'stacking cont…

…ainer', per fantasai suggestion

css-position-4/Overview.bs

@@ -118,7 +118,7 @@ with its top left corner at the canvas origin.
 
  1. For each of |root|'s non-positioned floating descendants,
  in tree order,
- [=paint a fake stacking context=]
+ [=paint a stacking container=]
  given the descendant and |canvas|.
 
  1.
@@ -155,7 +155,7 @@ with its top left corner at the canvas origin.
 
  <dl class=switch>
  : descendant has ''z-index: auto''
- :: [=Paint a fake stacking context=]
+ :: [=Paint a stacking container=]
  given the descendant and |canvas|.
 
  : descendant has ''z-index: 0''
@@ -266,7 +266,7 @@ with its top left corner at the canvas origin.
  and |canvas|.
 
  : If |root| is an [=inline-level=] [=block box|block=] or [=table wrapper box=]
- :: [=Paint a fake stacking context=]
+ :: [=Paint a stacking container=]
  given |root| and |canvas|.
 
  : If |root| is an [=inline-level=] replaced element
@@ -280,7 +280,7 @@ with its top left corner at the canvas origin.
 </div>
 
 <div algorithm>
- To <dfn>paint a fake stacking context</dfn>,
+ To <dfn>paint a stacking container</dfn>,
  given a [=box=] |root|
  and a canvas |canvas|: