Parser: vectorization attributes

Goal

Parse the three vectorization attributes via the approved #name(…) attribute grammar.

Implementation Sketch

Attach #vectorize / #no_vectorize / #fast_math to function declarations as synthetic attribute nodes; canonical attribute-order placement per Annex D.

Spec References

Proposal §5 attributes; Spec & Grammar Impact; simplified-attributes-proposal.md.

Work Items

• Parse #vectorize / #no_vectorize / #fast_math via the #name(…) attribute grammar and attach them to function declarations.
• Reject the attributes in invalid positions; matrix-test attribute placement (function vs type vs expression).