[llvm] [mlir] [MLIR] Migrate pattern application / dialect conversion to the LDBG logging format (PR #150991)

[Mehdi Amini via llvm-commits]

================
@@ -223,9 +221,8 @@ LogicalResult PatternApplicator::matchAndRewrite(
                 [&] { rewriter.setListener(oldListener); });
 #endif
             result = pattern->matchAndRewrite(op, rewriter);
-            LLVM_DEBUG(llvm::dbgs()
-                       << "\"" << bestPattern->getDebugName() << "\" result "
----------------
joker-eph wrote:

I removed it because in practice this is really noisy. The log will be:
```
[pattern-application:1] PatternApplicator.cpp:209 Trying to match "mlir::VectorConvertToLLVMPattern<mlir::math::FmaOp, mlir::LLVM::FMAOp, (anonymous namespace)::ConvertFastMath>"
[pattern-application:1] PatternApplicator.cpp:224  -> matchAndRewrite successful
```

Repeating the entire name didn't help readability here.

https://github.com/llvm/llvm-project/pull/150991