AsmMatcherEmitter: Non-deterministic sorting of ClassInfo may break reproducibility

There are cases where ClassInfo lists in llvm/utils/TableGen/AsmMatcherEmitter.cpp are sorted non-deterministically if ValueName fields are identical. This doesn’t break correctness, but it can cause non-reproducible builds, both at the source and binary level.

The fix is simple: after comparing ValueName, add a tie-break using the Name field so that the sorting is always deterministic. For example:

`- return ValueName < RHS.ValueName;
--------
+ if (ValueName != RHS.ValueName)
+ return ValueName < RHS.ValueName;
+ // All else being equal, we should sort by name, for source and binary reproducibility
+ return Name < RHS.Name;`

This ensures that identical ValueNames are always ordered the same way, making builds reproducible. It’s a very low risk change because it doesn’t change the behavior of the matcher, only the order in which classes appear in generated tables.

This issue was originally discussed in [https://reviews.llvm.org/D97477]
but the patch never made it upstream. I’ve seen the same problem in LLVM 21. Should I open a PR to upstream this fix?