SIL: Remove some obsolete mentions of 'uncurry level' from TypeLowering

Author: slavapestov

include/swift/SIL/TypeLowering.h

@@ -565,13 +565,6 @@ class TypeConverter {
 
   llvm::BumpPtrAllocator IndependentBPA;
 
-  enum : unsigned {
-    /// There is a unique entry with this uncurry level in the
-    /// type-lowering map for every TLI we create.  The map has the
-    /// responsibility to call the destructor for these entries.
-    UniqueLoweringEntry = ~0U
-  };
-
   struct CachingTypeKey {
     GenericSignature *Sig;
     AbstractionPattern::CachingKey OrigType;

lib/SIL/TypeLowering.cpp

@@ -1582,9 +1582,6 @@ TypeConverter::getTypeLoweringForLoweredType(TypeKey key,
   assert(type->isLegalSILType() && "type is not lowered!");
   (void)type;
 
-  // Re-using uncurry level 0 is reasonable because our uncurrying
-  // transforms are idempotent at this level.  This means we don't
-  // need a ton of redundant entries in the map.
   const TypeLowering *lowering = find(key);
   if (!lowering) {
     lowering = &getTypeLoweringForUncachedLoweredType(key);