When performing name lookup for the previous declaration of a field,
be sure to consider all of the possible lookup results. We were
assert()'ing (but behaving correctly) for unresolved values. Fixes
PR11134 / <rdar://problem/10290422>.

llvm-svn: 142652
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index c7873fa..f554cff 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -8421,16 +8421,25 @@
       << 2;
   
   // Check to see if this name was declared as a member previously
+  NamedDecl *PrevDecl = 0;
   LookupResult Previous(*this, II, Loc, LookupMemberName, ForRedeclaration);
   LookupName(Previous, S);
-  assert((Previous.empty() || Previous.isOverloadedResult() || 
-          Previous.isSingleResult()) 
-    && "Lookup of member name should be either overloaded, single or null");
-
-  // If the name is overloaded then get any declaration else get the single 
-  // result
-  NamedDecl *PrevDecl = Previous.isOverloadedResult() ?
-    Previous.getRepresentativeDecl() : Previous.getAsSingle<NamedDecl>();
+  switch (Previous.getResultKind()) {
+    case LookupResult::Found:
+    case LookupResult::FoundUnresolvedValue:
+      PrevDecl = Previous.getAsSingle<NamedDecl>();
+      break;
+      
+    case LookupResult::FoundOverloaded:
+      PrevDecl = Previous.getRepresentativeDecl();
+      break;
+      
+    case LookupResult::NotFound:
+    case LookupResult::NotFoundInCurrentInstantiation:
+    case LookupResult::Ambiguous:
+      break;
+  }
+  Previous.suppressDiagnostics();
 
   if (PrevDecl && PrevDecl->isTemplateParameter()) {
     // Maybe we will complain about the shadowed template parameter.