[CS] Remove a couple of dead types

Author: hamishknight

lib/Sema/CSApply.cpp

@@ -1005,9 +1005,6 @@ namespace {
 
       return finishApply(apply, memberRef, openedType, locator);
     }
-    
-    /// Describes either a type or the name of a type to be resolved.
-    using TypeOrName = llvm::PointerUnion<Identifier, Type>;
 
     /// Convert the given literal expression via a protocol pair.
     ///

lib/Sema/ConstraintSystem.h

@@ -804,13 +804,6 @@ class SolutionDiff {
   explicit SolutionDiff(ArrayRef<Solution> solutions);
 };
 
-/// Identifies a specific conversion from
-struct SpecificConstraint {
-  CanType First;
-  CanType Second;
-  ConstraintKind Kind;
-};
-
 /// An intrusive, doubly-linked list of constraints.
 using ConstraintList = llvm::ilist<Constraint>;