vectorTypeAssumeCapacity

fn vectorTypeAssumeCapacity(
    self: *Builder,
    comptime kind: Type.Vector.Kind,
    len: u32,
    child: Type,
) Type {
    assert(child.isFloatingPoint() or child.isInteger(self) or child.isPointer(self));
    const tag: Type.Tag = switch (kind) {
        .normal => .vector,
        .scalable => .scalable_vector,
    };
    const Adapter = struct {
        builder: *const Builder,
        pub fn hash(_: @This(), key: Type.Vector) u32 {
            return @truncate(std.hash.Wyhash.hash(
                comptime std.hash.int(@backingInt(tag)),
                std.mem.asBytes(&key),
            ));
        }
        pub fn eql(ctx: @This(), lhs_key: Type.Vector, _: void, rhs_index: usize) bool {
            const rhs_data = ctx.builder.type_items.items[rhs_index];
            return rhs_data.tag == tag and
                std.meta.eql(lhs_key, ctx.builder.typeExtraData(Type.Vector, rhs_data.data));
        }
    };
    const data = Type.Vector{ .len = len, .child = child };
    const gop = self.type_map.getOrPutAssumeCapacityAdapted(data, Adapter{ .builder = self });
    if (!gop.found_existing) {
        gop.key_ptr.* = {};
        gop.value_ptr.* = {};
        self.type_items.appendAssumeCapacity(.{
            .tag = tag,
            .data = self.addTypeExtraAssumeCapacity(data),
        });
    }
    return @fromBackingInt(@intCast(gop.index));
}