Set the base remapping of FACE in the current buffer to SPECS.
This causes the remappings specified by `face-remap-add-relative'
to apply on top of the face specification given by SPECS.
The remaining arguments, SPECS, should form a list of faces.
Each list element should be either a face name or a property list
of face attribute/value pairs, like in a `face' text property.
If SPECS is empty, call `face-remap-reset-base' to use the normal
definition of FACE as the base remapping; note that this is
different from SPECS containing a single value `nil', which means
not to inherit from the global definition of FACE at all. (fn FACE &rest SPECS)