[mlir][Transform] Allow printing inside matchers

[qedawkins]

Summary

Enables printf style debugging of matchers through transform.print
within the body of a matcher.

mlir/include/mlir/Dialect/Transform/IR/TransformOps.td

def ParamConstantOp : Op<Transform_Dialect, "param.constant", [
   }];
   let arguments = (ins AnyAttr:$value);
   let results = (outs TransformParamTypeInterface:$param);
   let assemblyFormat = "$value attr-dict `->` type($param)";
 }
 
 def PrintOp : TransformDialectOp<"print",
     [DeclareOpInterfaceMethods<TransformOpInterface>,
-     DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
+     DeclareOpInterfaceMethods<MemoryEffectsOpInterface>,
+     MatchOpInterface]> {
   let summary = "Dump each payload op";
   let description = [{
     This op dumps each payload op that is associated with the `target` operand
     to stderr. It also prints the `name` string attribute. If no target is
     specified, the top-level op is dumped.
 
     This op is useful for printf-style debugging.
   }];

mlir/test/Dialect/Linalg/match-ops-interpreter.mlir

 
 // -----
 
 module attributes { transform.with_named_sequence } {
   transform.named_sequence @do_nothing(%arg0: !transform.any_op {transform.readonly}) {
     transform.yield
   }
 
+  transform.named_sequence @print_in_matcher(%arg0: !transform.any_op {transform.readonly}) -> !transform.any_op {
+    transform.print %arg0 : !transform.any_op
+    transform.yield %arg0 : !transform.any_op
+  }
+
+  transform.sequence failures(propagate) attributes { transform.target_tag = "transform" } {
+  ^bb0(%arg0: !transform.any_op):
+    transform.foreach_match in %arg0
+        @print_in_matcher -> @do_nothing
+        : (!transform.any_op) -> !transform.any_op
+  }
+
+  func.func @payload() attributes { transform.target_tag = "start_here" } {
+    // CHECK: [[ IR Printer ]]
+    // CHECK: test.print_me
+    %0 = "test.print_me"() : () -> (i1)
+    return
+  }
+}
+
+// -----
+
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @do_nothing(%arg0: !transform.any_op {transform.readonly}) {
+    transform.yield
+  }
+
   // Entry point. Match any structured operation and emit a remark. Also emit
   // a different remark at all considered operations. When it fails, the
   // failure is suppressed and the resulting handle is assocaited with an empty
   // list, hence nothing is printed. Both remark printing operations happen
   // after the check in the sequence, so they only apply if the check operation
   // produced success (due to failure suppression or not).
   transform.named_sequence @match_structured_suppress(%arg0: !transform.any_op {transform.readonly}) -> !transform.any_op {
     %0 = transform.match.structured failures(suppress) %arg0 : (!transform.any_op) -> !transform.any_op {