Fix #23166 Set sc3.minst to root module

[gulugulubing]

This is related to #23166. RTInfoImpl!([32, 9]) is not emitted when codegen, because it is categerized in c module.
And reordering the field may change RTInfoImpl!([32, 9]) to RTInfoImpl!([32, 10]), which accidently is defined in phobos.

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[thewilsonator]

otherwise looks good