[FIRRTL] Use InstanceInfo in MemToRegOfVec

Change the MemToRegOfVec pass to use the InstanceInfo analysis.  This does
subtly change the semantic of what is considered "in the design" to now
treat layers and Grand Central Companions as "outside" the design.  This
should be safe.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@sifive.com>

lib/Dialect/FIRRTL/Transforms/MemToRegOfVec.cpp

@@ -10,15 +10,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "circt/Analysis/FIRRTLInstanceInfo.h"
 #include "circt/Dialect/FIRRTL/AnnotationDetails.h"
 #include "circt/Dialect/FIRRTL/FIRRTLAnnotations.h"
-#include "circt/Dialect/FIRRTL/FIRRTLInstanceGraph.h"
 #include "circt/Dialect/FIRRTL/FIRRTLOps.h"
 #include "circt/Dialect/FIRRTL/FIRRTLTypes.h"
 #include "circt/Dialect/FIRRTL/Passes.h"
 #include "mlir/IR/Threading.h"
 #include "mlir/Pass/Pass.h"
-#include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/Support/Debug.h"
 
 #define DEBUG_TYPE "mem-to-reg-of-vec"
@@ -41,27 +40,16 @@ struct MemToRegOfVecPass
 
   void runOnOperation() override {
     auto circtOp = getOperation();
-    DenseSet<Operation *> dutModuleSet;
+    auto &instanceInfo = getAnalysis<InstanceInfo>();
+
     if (!AnnotationSet::removeAnnotations(circtOp,
                                           convertMemToRegOfVecAnnoClass))
       return markAllAnalysesPreserved();
-    auto *body = circtOp.getBodyBlock();
 
-    // Find the device under test and create a set of all modules underneath it.
-    auto it = llvm::find_if(*body, [&](Operation &op) -> bool {
-      return AnnotationSet::hasAnnotation(&op, dutAnnoClass);
-    });
-    if (it != body->end()) {
-      auto &instanceGraph = getAnalysis<InstanceGraph>();
-      auto *node = instanceGraph.lookup(cast<igraph::ModuleOpInterface>(*it));
-      llvm::for_each(llvm::depth_first(node),
-                     [&](igraph::InstanceGraphNode *node) {
-                       dutModuleSet.insert(node->getModule());
-                     });
-    } else {
-      auto mods = circtOp.getOps<FModuleOp>();
-      dutModuleSet.insert(mods.begin(), mods.end());
-    }
+    DenseSet<Operation *> dutModuleSet;
+    for (auto moduleOp : circtOp.getOps<FModuleOp>())
+      if (instanceInfo.anyInstanceInEffectiveDesign(moduleOp))
+        dutModuleSet.insert(moduleOp);
 
     mlir::parallelForEach(circtOp.getContext(), dutModuleSet,
                           [&](Operation *op) {