"Identifier not used" is weird, replace it by "unknown identifier" and
give the search identifier name in the header.
Also improve the autocomplete comment. Make it human-friendly and
explain why people got autocompleted to a symbol that does not exist.
Also, only show it if the symbol actually exists. That way we only
tell "maybe autocomplete lead you here" only in cases where
autocomplete can actually lead you here.
To test this feature:
- search for any random symbol, you'll see "Unknown identifier '...'"
- search for a symbol that exists in another version as the selected
one. For example __NR_epoll_pwait2 appeared in musl v1.2.5. You'll
see the same header message plus a comment about how the symbol
exists in another version.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
