[CSStep] List type variables in scope under consideration for each component step.

Author: Amritpan Kaur

lib/Sema/CSStep.h

@@ -466,11 +466,29 @@ class ComponentStep final : public SolverStep {
     // to preliminary modify constraint system or log anything.
     if (IsSingle)
       return;
-
-    if (CS.isDebugMode())
-      getDebugLogger() << "(solving component #" << Index << '\n';
-
+    
+    if (CS.isDebugMode()) {
+      auto &log = getDebugLogger();
+      log << "(solving component #" << Index << '\n';
+    }
+    
     ComponentScope = std::make_unique<Scope>(*this);
+    
+    if (CS.isDebugMode()) {
+      auto &log = getDebugLogger();
+      log << "Type variables in scope = "
+          << "[";
+      auto typeVars = CS.getTypeVariables();
+      PrintOptions PO;
+      PO.PrintTypesForDebugging = true;
+      interleave(typeVars, [&](TypeVariableType *typeVar) {
+                   Type(typeVar).print(log, PO);
+                 },
+                 [&] {
+                   log << ", ";
+                 });
+      log << "]" << '\n';
+    }
 
     // If this component has orphaned constraint attached,
     // let's return it to the graph.