[NFC][SeqToSV] Fix constant caching in FIR mem loweringi

Author: nandor

lib/Conversion/SeqToSV/FirMemLowering.cpp

@@ -307,14 +307,15 @@ void FirMemLowering::lowerMemoriesInModule(
   LLVM_DEBUG(llvm::dbgs() << "Lowering " << mems.size() << " memories in "
                           << module.getName() << "\n");
 
-  hw::ConstantOp constOneOp;
+  DenseMap<unsigned, Value> constOneOps;
   auto constOne = [&](unsigned width = 1) {
-    if (!constOneOp) {
+    auto it = constOneOps.try_emplace(width, Value{});
+    if (it.second) {
       auto builder = OpBuilder::atBlockBegin(module.getBodyBlock());
-      constOneOp = builder.create<hw::ConstantOp>(
+      it.first->second = builder.create<hw::ConstantOp>(
           module.getLoc(), builder.getIntegerType(width), 1);
     }
-    return constOneOp;
+    return it.first->second;
   };
   auto valueOrOne = [&](Value value, unsigned width = 1) {
     return value ? value : constOne(width);