Update comments

Author: calda

lib/Sema/MiscDiagnostics.cpp

@@ -1530,9 +1530,10 @@ static void diagnoseImplicitSelfUseInClosure(const Expr *E,
       auto isExplicitWeakSelfCapture = false;
       if (auto closureExpr = dyn_cast<ClosureExpr>(inClosure)) {
         if (auto selfDecl = closureExpr->getCapturedSelfDecl()) {
-          // If `weak self` captured explicitly, then implicit self
+          // If `weak self` was captured explicitly, then implicit self
           // is always allowed allowed once `self` is unwrapped.
-          //  - If `self` is still an Optional, compilation would have failed already.
+          //  - If `self` is still an Optional, compilation would have failed already,
+          //    so we don't need to check for that here.
           if (selfDecl->getType()->is<WeakStorageType>()) {
             isExplicitWeakSelfCapture = true;
           }

lib/Sema/PreCheckExpr.cpp

@@ -747,7 +747,7 @@ Expr *TypeChecker::resolveDeclRefExpr(UnresolvedDeclRefExpr *UDRE,
     } else {
       // If this is an implicit self reference, the `VarDecl` will
       // currently have a non-optional type. But at this point,
-      // we don't actually know if this is corret (it could be a
+      // we don't actually know if this is correct (it could be a
       // weak self capture that hasn't been unwrapped yet).
       //  - Since we don't know the correct type of self yet,
       //    we leave this as an UnresolvedDeclRefExpr that is