Simplify code (and remove 'dyn_cast') by using ObjCProperyDecl::findPropertyDecl().

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@98794 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaObjCProperty.cpp b/lib/Sema/SemaObjCProperty.cpp
index 3a0fe0a..41ed6c6 100644
--- a/lib/Sema/SemaObjCProperty.cpp
+++ b/lib/Sema/SemaObjCProperty.cpp
@@ -137,17 +137,9 @@
       Diag(AtLoc, diag::warn_property_attr_mismatch);
       Diag(PIDecl->getLocation(), diag::note_property_declare);
     }
-    DeclContext *DC = dyn_cast<DeclContext>(CCPrimary);
-    assert(DC && "ClassDecl is not a DeclContext");
-    DeclContext::lookup_result Found =
-    DC->lookup(PIDecl->getDeclName());
-    bool PropertyInPrimaryClass = false;
-    for (; Found.first != Found.second; ++Found.first)
-      if (isa<ObjCPropertyDecl>(*Found.first)) {
-        PropertyInPrimaryClass = true;
-        break;
-      }
-    if (!PropertyInPrimaryClass) {
+    DeclContext *DC = cast<DeclContext>(CCPrimary);
+    if (!ObjCPropertyDecl::findPropertyDecl(DC,
+                                 PIDecl->getDeclName().getAsIdentifierInfo())) {
       // Protocol is not in the primary class. Must build one for it.
       ObjCDeclSpec ProtocolPropertyODS;
       // FIXME. Assuming that ObjCDeclSpec::ObjCPropertyAttributeKind