[css-grid-1] Restore the first fit-content() clamping, which does indeed need to stay around. Whoops. w3c#4549

Author: tabatkins

css-grid-1/Overview.bs

@@ -4120,6 +4120,8 @@ Resolve Intrinsic Track Sizes</h3>
 					If the track has a ''max-content'' <a>max track sizing function</a>,
 					set its <a>growth limit</a>
 					to the maximum of the items’ <a>max-content contributions</a>.
+					For ''fit-content()'' maximums,
+					furthermore clamp this <a>growth limit</a> by the ''fit-content()'' argument.
 			</dl>
 
 			In all cases, if a track’s <a>growth limit</a> is now less than its <a>base size</a>,