Extend the OpDSL syntax with an optional `domain` function to specify an explicit dimension order. The extension is needed to provide more control over the dimension order instead of deducing it implicitly depending on the formulation of the tensor comprehension. Additionally, the patch also ensures the symbols are ordered according to the operand definitions of the operation.
Differential Revision: https://reviews.llvm.org/D105117
* NFC but has some fixes for CMake glitches discovered along the way (things not cleaning properly, co-mingled depends).
* Includes previously unsubmitted fix in D98681 and a TODO to fix it more appropriately in a smaller followup.
Differential Revision: https://reviews.llvm.org/D101493
