[GSB] Eliminate the ridiculous ad hoc recursion-breaking code.

We're now properly delaying all recursive requirements, so we no
longer need to compute `grossCount`.

Author: DougGregor

lib/AST/GenericSignatureBuilder.cpp

@@ -1063,37 +1063,6 @@ bool FloatingRequirementSource::isRecursive(
       return true;
   }
 
-  // For a nested type match, look for another type with that name.
-  // FIXME: Actually, look for 5 of them. This is totally bogus.
-  if (kind == NestedTypeNameMatch) {
-    unsigned grossCount = 0;
-    auto pa = storage.dyn_cast<const RequirementSource *>()
-                ->getAffectedPotentialArchetype();
-    while (auto parent = pa->getParent()) {
-      if (pa->getNestedName() == nestedName) {
-        if (++grossCount > 4) {
-          ++NumRecursive;
-          return true;
-        }
-      }
-
-      pa = parent;
-    }
-
-    // Also check the root type.
-    grossCount = 0;
-    for (Type type = rootType;
-         auto depTy = type->getAs<DependentMemberType>();
-         type = depTy->getBase()) {
-      if (depTy->getName() == nestedName) {
-        if (++grossCount > 4) {
-          ++NumRecursive;
-          return true;
-        }
-      }
-    }
-  }
-
   return false;
 }