5.8-arduino9: C++: mitigate matching error on generics containing an expression
backport of https://github.com/geany/geany/commit/d40932ce4d05e57573a6d6c8f89f4aea8c42d4f3
backport of https://github.com/geany/geany/commit/d40932ce4d05e57573a6d6c8f89f4aea8c42d4f3