gemspec mapping: Add support for optional parameter
We currently match gemspec files with this regexp: .*Gem::Specification.new +(do|\{) +\|.*\|.*, which works for most of them.
However, some take optional arguments, for example: https://archive.softwareheritage.org/browse/revision/5a84219de709969801b3c95a7103d369e2333d64/?path=kennel.gemspec and https://archive.softwareheritage.org/browse/revision/04e0d2c7edde2321ea5260602383005d5f71d3d1/?path=parallel_tests.gemspec
We should add support for them, and at least substitute the name in the rest of the gem specification
Migrated from T4490 (view on Phabricator)