[llvm] [mlir] [MLIR] Adopt LDBG() in EliminateBarriers.cpp (NFC) (PR #155092)

[Jacques Pienaar via llvm-commits]

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@@ -424,27 +422,18 @@ static bool maybeCaptured(Value v) {
 /// everything. This seems sufficient to achieve barrier removal in structured
 /// control flow, more complex cases would require a proper dataflow analysis.
 static bool mayAlias(Value first, Value second) {
-  DEBUG_WITH_TYPE(DEBUG_TYPE_ALIAS, {
-    DBGS_ALIAS() << "checking aliasing between ";
-    DBGS_ALIAS() << first << "\n";
-    DBGS_ALIAS() << "                      and ";
-    DBGS_ALIAS() << second << "\n";
-  });
+  LDBG(1, DEBUG_TYPE_ALIAS)
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jpienaar wrote:

I know this is following default arguments are last kind of C++ style, but I think the opposite reads nicer here:

```
LDBG(DEBUG_TYPE, 1)
```

As the former is the higher-level filter and the latter the level within that. Thinking out loud, I wonder: could we even overload on type here? (so `LDBG(DEBUG_TYPE)` could work too).

https://github.com/llvm/llvm-project/pull/155092