[TLX][AMD] DotConsumerBackward: comment empty pure-virtual overrides

Note that the empty bodies are intentional for an info-only lattice:
unanalyzed cases stay Uninitialized, which findDotConsumer treats the
same as Conflict, and the caller falls back to the default encoding.
This contrasts with DotRewriteBackward (legality analysis) which has
to poison unanalyzed paths.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: Hardcode84

third_party/tlx/dialect/lib/Transforms/InsertRequireLayout.cpp

@@ -523,6 +523,11 @@ class DotConsumerBackward
     return success();
   }
 
+  // Required pure-virtual overrides. This is an info-only lattice (not a
+  // legality analysis like DotRewriteBackward, which poisons here): leaving
+  // unanalyzed cases as Uninitialized is safe because findDotConsumer
+  // returns nullopt for both Uninitialized and Conflict, and the caller
+  // falls back to buildDefaultTDMDescriptorEncoding.
   void visitBranchOperand(OpOperand &) override {}
   void visitCallOperand(OpOperand &) override {}
   void setToExitState(DotConsumerLattice *) override {}