FindRuby: Restore compatibility variable RUBY_INCLUDE_PATH
Since commit e672db628b (FindRuby: Rename variables to match case of
module name, 2020-03-11, v3.18.0-rc1~546^2), the result variables named
with the old `RUBY_` prefix are provided by compatibility code that maps
from the new `Ruby_` prefix variables. There is no `Ruby_INCLUDE_PATH`
variable, so do not try to map it to `RUBY_INCLUDE_PATH`. The latter is
provided by dedicated compatibility code left from before that
transition.
Fixes: #21064
1 file changed
