[mdspan.layout.leftpad.cons] Add \exposid for static-padding-stride

Author: hewillk

source/containers.tex

@@ -21949,9 +21949,9 @@
 \mandates
 If \tcode{OtherExtents::rank()} is greater than \tcode{1}, then
 \begin{codeblock}
-(static-padding-stride== dynamic_extent) ||
+(@\exposid{static-padding-stride}@ == dynamic_extent) ||
 (OtherExtents::static_extent(0) == dynamic_extent) ||
-(static-padding-stride== OtherExtents::static_extent(0))
+(@\exposid{static-padding-stride}@ == OtherExtents::static_extent(0))
 \end{codeblock}
 is \tcode{true}.