File.absolute_path returns absolute path for relative classpath:uri #8981
Description
Discovered while working on specs in #8980 and adding spec:jruby run to macos.
File.absolute_path appears to absolutize a relative classpath:uri: path on macos but apparently not on Linux. This leads to a failure in spec:jruby:
1) File#absolute_path should return itself for 'classpath:uri:/'
Failure/Error: DEFAULT_FAILURE_NOTIFIER = lambda { |failure, _opts| raise failure }
expected: "classpath:uri:/home/me"
got: "classpath:uri:/System/Volumes/Data/home/me"
(compared using ==)
# ./spec/jruby/core/file/absolute_path_spec.rb:19:in `block in <main>'
# ./spec/jruby/core/file/absolute_path_spec.rb:18:in `block in <main>'
This does not appear to be related to the breakage reported in #8973 or the fixes for it.