Asciidoc writer: ensure correct nesting strong/emph.

Closes #5565.

src/Text/Pandoc/Writers/AsciiDoc.hs

@@ -405,6 +405,8 @@ withIntraword p = setIntraword True *> p <* setIntraword False
 
 -- | Convert Pandoc inline element to asciidoc.
 inlineToAsciiDoc :: PandocMonad m => WriterOptions -> Inline -> ADW m Doc
+inlineToAsciiDoc opts (Emph [Strong xs]) =
+  inlineToAsciiDoc opts (Strong [Emph xs])  -- see #5565
 inlineToAsciiDoc opts (Emph lst) = do
   contents <- inlineListToAsciiDoc opts lst
   isIntraword <- gets intraword

test/command/5565.md

@@ -0,0 +1,6 @@
+```
+% pandoc -t asciidoc
+***hi***
+^D
+*_hi_*
+```