[Ada] Fix references to Backend_Layout configuration parameter
Apparently the Backend_Layout target configuration parameter was renamed to
Frontend_Layout a long time ago (and their meanings are opposite). However,
some comments were still referencing the no longer existing Backend_Layout.
This patch fixes such references.
No test provided, because only comments has been modified.
2018-05-24 Piotr Trojanek <trojanek@adacore.com>
gcc/ada/
* layout.ads, repinfo.ads: Fix references to renamed Backend_Layout
configuration parameter.
From-SVN: r260642