Improve ApplyRegisteredPassOp's support for taking options by taking
them as a dict (vs a list of string-valued key-value pairs).
Values of options are provided as either static attributes or as params
(which pass in attributes at interpreter runtime). In either case, the
keys and value attributes are converted to strings and a single
options-string, in the format used on the commandline, is constructed to
pass to the `addToPipeline`-pass API.
fe7bf4b90b