This reverts commit 5e7d42f, which is a change seemingly meant for the glr branch. Breaks on nom.
Some of the tests for different forms of Rat literals did so in a way that calls will call .Numeric on Str (as well as any other non-Numeric argument). Since a Rat literal that's not parsed correctly will be interpreted as a Str, then as long as Str.Numeric can handle the given Rat form any issues with Rat literals for those forms were hidden. These tests were changed to ensure we don't numify any strings. Also updated some of the tests to use the new 'does-ok' to check roles, and replaced a smartmatch against Str with an 'isa-ok' check.