Refine logic for laying out flex item in column layout after #34346 (#34372)

- Clamp the stretch size to not be negative when the sum of padding,
  borders and margins exceed the available space. This avoids a 2nd
  layout.
- Avoid computing the inline content sizes if the result isn't needed.
- Instead of clamping both the min-content and max-content sizes to be
  between the min and max constraints, just compute the fit-content size
  first, and then clamp. Then `ContentSizes::map()` can be removed.

Signed-off-by: Oriol Brufau <obrufau@igalia.com>

components/layout_2020/sizing.rs

@@ -40,13 +40,6 @@ pub(crate) struct ContentSizes {
 
 /// <https://drafts.csswg.org/css-sizing/#intrinsic-sizes>
 impl ContentSizes {
-    pub fn map(&self, f: impl Fn(Au) -> Au) -> Self {
-        Self {
-            min_content: f(self.min_content),
-            max_content: f(self.max_content),
-        }
-    }
-
     pub fn max(&self, other: Self) -> Self {
         Self {
             min_content: self.min_content.max(other.min_content),