Generalize MaxAndArgmax to all Commutative Operations and Datatypes and all Destination Tensor Sizes

[obilaniu]

Added multiple new reduction ops, enumerated in enum ga_reduce_op, and also heavily refactored internally in preparation to add a generator for "small code model" kernels, which will be used for reductions with a small destination.

typedef enum _ga_reduce_op {
	GA_REDUCE_SUM,             /*        +        */
	GA_REDUCE_PROD,            /*        *        */
	GA_REDUCE_PRODNZ,          /*        * (!=0)  */
	GA_REDUCE_MIN,             /*      min()      */
	GA_REDUCE_MAX,             /*      max()      */
	GA_REDUCE_ARGMIN,          /*     argmin()    */
	GA_REDUCE_ARGMAX,          /*     argmax()    */
	GA_REDUCE_MINANDARGMIN,    /* min(), argmin() */
	GA_REDUCE_MAXANDARGMAX,    /* max(), argmax() */
	GA_REDUCE_AND,             /*        &        */
	GA_REDUCE_OR,              /*        |        */
	GA_REDUCE_XOR,             /*        ^        */
	GA_REDUCE_ALL,             /*     &&/all()    */
	GA_REDUCE_ANY,             /*     ||/any()    */
} ga_reduce_op;