[Feature Request] add support for generic function

[deepkolos]

namespace gl {
  export declare function bufferData<T>(target: GLenum, data: StaticArray<T>, usage: GLenum): void;
}

FAILURE Can’t import or export generic functions.

[torch2424]

@deepkolos Ah! Thank you for finding this bug! Would you be open to opening a PR for this one as well? 😄