Stop randomly stripping IdentityExprs from recursive positions

within accessors.

Improves source fidelity and fixes problems with error handling
(because TryExpr and ForceTryExpr are IdentityExprs).

Swift SVN r28298

lib/Sema/MiscDiagnostics.cpp

@@ -353,10 +353,6 @@ static void diagRecursivePropertyAccess(TypeChecker &TC, const Expr *E,
           }
         }
 
-      } else if (auto *PE = dyn_cast<IdentityExpr>(E)) {
-        // Look through ParenExprs because a function argument of a single
-        // rvalue will have a LoadExpr /outside/ the ParenExpr.
-        return { true, PE->getSubExpr() };
       }
 
       return { true, E };

test/stmt/errors.swift

@@ -54,3 +54,15 @@ func six() {
   } catch _ {
   }
 }
+
+func seven_helper() throws -> Int { throw MSV.Baz }
+
+struct seven {
+  var x: Int {
+    do {
+      return try seven_helper()
+    } catch {
+      return 0
+    }
+  }
+}