[MLIR][OneShotBufferize] Fix opFilter init

OneShotBufferizePass's opFilter definition in runOnOperation() fails to
allow operations for all dialect when the dialectFilter has an empty
array value (as opposed to no value). This happens when constructing
OneShotBufferizePass from a OneShotBufferizePassOptions parameter with
an empty dialectFilter. This commit only does filtering if filterDialect
option has a value and it is not an empty array.

Author: RoboTux

mlir/lib/Dialect/Bufferization/Transforms/Bufferize.cpp

@@ -142,7 +142,7 @@ struct OneShotBufferizePass
       // Configure op filter.
       OpFilter::Entry::FilterFn filterFn = [&](Operation *op) {
         // Filter may be specified via options.
-        if (this->dialectFilter.hasValue())
+        if (this->dialectFilter.hasValue() && !(*this->dialectFilter).empty())
           return llvm::is_contained(this->dialectFilter,
                                     op->getDialect()->getNamespace());
         // No filter specified: All other ops are allowed.