[J3] Effect of RESULT_IMAGE in CO_xyz intrinsics

[van snyder]

CO_MAX, CO_MIN, CO_REDUCE, and CO_SUM have a RESULT_IMAGE argument. The description says that its value shall be an integer that is an image index in the current team. The effect of it being present is hiding in the description of the argument named A. That description says that the result of the operation appears in A, and appears also to say that if RESULT_IMAGE is present and its value is not the index of the executing image, the value of A on that image becomes undefined.
This is a bit confusing.
Does A really become undefined on all images other than the one indexed by RESULT_IMAGE? I naively would have expected it to remain unchanged. If it's used for work space, a note to that effect would be useful.

One might expect the value of A on all images to be the same if RESULT_IMAGE is not present.  The description of A seems to say that, but doesn't explicitly say so.

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