[llvm] [Offload] Add `MAX_WORK_GROUP_SIZE` device info query (PR #143718)

[Ross Brunton via llvm-commits]

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@@ -13,6 +13,8 @@
 
 #include "OffloadImpl.hpp"
 #include "Helpers.hpp"
+// Required for operator<< implementation of ol_device_info_t
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RossBrunton wrote:

My IDE has decided that `OffloadPrint.hpp` is unused, so I just added the comment to ward off any would be code cleaners. I'll put it on the same line though.

https://github.com/llvm/llvm-project/pull/143718