Rust: Fix bad join

[hvitved]

Before

Evaluated relational algebra for predicate TypeMention::RefTypeReprMention.resolveRootType/0#dispred#091b949a#fb@4bd8a49g with tuple counts:
            124419   ~0%    {1} r1 = RefTypeRepr::Generated::RefTypeRepr#422893fa AND NOT `RefTypeRepr::Generated::RefTypeRepr.isMut/0#dispred#e2b9988f`(FIRST 1)
        6621454761   ~1%    {3}    | JOIN WITH `Type::DataType.getTypeItem/0#dispred#83467854` CARTESIAN PRODUCT OUTPUT Rhs.0, Lhs.0, Rhs.1
         915101745   ~0%    {4}    | JOIN WITH `project#Type::DataType.getPositionalTypeParameter/1#dispred#3bf49cbe` ON FIRST 1 OUTPUT Lhs.2, _, Lhs.1, Lhs.0
         915101745   ~3%    {4}    | REWRITE WITH Out.1 := "Ref"
            124419   ~0%    {2}    | JOIN WITH `Builtins::BuiltinType.getName/0#dispred#8f62ab0a` ON FIRST 2 OUTPUT Lhs.2, Lhs.3

             76728   ~0%    {1} r2 = JOIN RefTypeRepr::Generated::RefTypeRepr#422893fa WITH `RefTypeRepr::Generated::RefTypeRepr.isMut/0#dispred#e2b9988f` ON FIRST 1 OUTPUT Lhs.0
        4083387432   ~1%    {3}    | JOIN WITH `Type::DataType.getTypeItem/0#dispred#83467854` CARTESIAN PRODUCT OUTPUT Rhs.0, Lhs.0, Rhs.1
         564334440   ~3%    {4}    | JOIN WITH `project#Type::DataType.getPositionalTypeParameter/1#dispred#3bf49cbe` ON FIRST 1 OUTPUT Lhs.2, _, Lhs.1, Lhs.0
         564334440   ~0%    {4}    | REWRITE WITH Out.1 := "RefMut"
             76728   ~2%    {2}    | JOIN WITH `Builtins::BuiltinType.getName/0#dispred#8f62ab0a` ON FIRST 2 OUTPUT Lhs.2, Lhs.3

            201147   ~1%    {2} r3 = r1 UNION r2
                            return r3

After

Evaluated relational algebra for predicate TypeMention::RefTypeReprMention.resolveRootType/0#dispred#091b949a#fb@8f12aa2a with tuple counts:
        124419   ~0%    {1} r1 = RefTypeRepr::Generated::RefTypeRepr#422893fa AND NOT `RefTypeRepr::Generated::RefTypeRepr.isMut/0#dispred#e2b9988f`(FIRST 1)
        124419   ~0%    {2}    | JOIN WITH Type::RefSharedType#090df68e CARTESIAN PRODUCT OUTPUT Rhs.0, Lhs.0
        124419   ~0%    {2}    | JOIN WITH `project#Type::DataType.getPositionalTypeParameter/1#dispred#3bf49cbe` ON FIRST 1 OUTPUT Lhs.1, Lhs.0

         76728   ~0%    {1} r2 = JOIN RefTypeRepr::Generated::RefTypeRepr#422893fa WITH `RefTypeRepr::Generated::RefTypeRepr.isMut/0#dispred#e2b9988f` ON FIRST 1 OUTPUT Lhs.0
         76728   ~0%    {2}    | JOIN WITH Type::RefMutType#c67a1837 CARTESIAN PRODUCT OUTPUT Rhs.0, Lhs.0
         76728   ~2%    {2}    | JOIN WITH `project#Type::DataType.getPositionalTypeParameter/1#dispred#3bf49cbe` ON FIRST 1 OUTPUT Lhs.1, Lhs.0

        201147   ~1%    {2} r3 = r1 UNION r2
                        return r3

[Copilot]

Pull request overview

This PR optimizes QL query performance by adding pragma[nomagic] annotations to type constructors in the Rust type inference library. The optimization prevents inefficient Cartesian product joins, reducing intermediate tuple counts from billions to thousands and improving query evaluation efficiency.

Changes:

• Added pragma[nomagic] annotations to 7 type constructor predicates to optimize join operations

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[geoffw0]

LGTM. 👍