* automake.in (%subobjvar): Replace by ...

* automake.in (%subobjvar): Replace by ...
(%gen_varname): ... this.
(subobjname): Replace by ...
(gen_varname): ... this.
(initialize_per_input): Clean gen_varname instead of subobjname.
(transform_variable_recursively): New function, extracted
from define_objects_from_sources.
(define_objects_from_sources): Use transform_variable_recursively.
Remove the unused $parent argument.
(handle_source_transform): Adjust call to define_objects_from_sources.