Remove some redundant post walks

Author: hamishknight

lib/Sema/CSGen.cpp

@@ -124,11 +124,7 @@ namespace {
 
       return Action::Continue(expr);
     }
-    
-    PostWalkResult<Expr *> walkToExprPost(Expr *expr) override {
-      return Action::Continue(expr);
-    }
-    
+
     /// Ignore statements.
     PreWalkResult<Stmt *> walkToStmtPre(Stmt *stmt) override {
       return Action::SkipChildren(stmt);
@@ -848,11 +844,6 @@ namespace {
 
       return Action::Continue(expr);
     }
-    
-    PostWalkResult<Expr *> walkToExprPost(Expr *expr) override {
-      return Action::Continue(expr);
-    }
-    
     /// Ignore statements.
     PreWalkResult<Stmt *> walkToStmtPre(Stmt *stmt) override {
       return Action::SkipChildren(stmt);

lib/Sema/MiscDiagnostics.cpp

@@ -360,10 +360,6 @@ static void diagSyntacticUseRestrictions(const Expr *E, const DeclContext *DC,
       return Action::Continue(E);
     }
 
-    PostWalkResult<Expr *> walkToExprPost(Expr *E) override {
-      return Action::Continue(E);
-    }
-
     /// Visit each component of the keypath and emit a diagnostic if they
     /// refer to a member that has effects.
     void checkForEffectfulKeyPath(KeyPathExpr *keyPath) {