[ASTImporter] Support new AST nodes:

 * UnresolvedUsingType
 * EmptyDecl
 * NamespaceAliasDecl
 * UsingDecl
 * UsingShadowDecl
 * UsingDirectiveDecl
 * UnresolvedUsingValueDecl
 * UnresolvedUsingTypenameDecl

Refactor error handling in ImportTemplateArgumentLoc() method.
Add a test for inline namespaces.

llvm-svn: 318776
diff --git a/clang/test/ASTMerge/namespace/Inputs/namespace1.cpp b/clang/test/ASTMerge/namespace/Inputs/namespace1.cpp
index 1ff84f3..4a53952 100644
--- a/clang/test/ASTMerge/namespace/Inputs/namespace1.cpp
+++ b/clang/test/ASTMerge/namespace/Inputs/namespace1.cpp
@@ -15,3 +15,13 @@
 namespace N3 {
   extern float z;
 }
+
+namespace AliasWithSameName = N3;
+
+namespace TestUnresolvedTypenameAndValueDecls {
+template <class T> class Base {
+public:
+  typedef T foo;
+  void bar();
+};
+}
diff --git a/clang/test/ASTMerge/namespace/Inputs/namespace2.cpp b/clang/test/ASTMerge/namespace/Inputs/namespace2.cpp
index 80429f7..f65057d 100644
--- a/clang/test/ASTMerge/namespace/Inputs/namespace2.cpp
+++ b/clang/test/ASTMerge/namespace/Inputs/namespace2.cpp
@@ -15,3 +15,46 @@
 namespace N3 {
   extern double z;
 }
+
+namespace Enclosing {
+namespace Nested {
+  const int z = 4;
+}
+}
+
+namespace ContainsInline {
+  inline namespace Inline {
+    const int z = 10;
+  }
+}
+
+namespace TestAliasName = Enclosing::Nested;
+// NOTE: There is no warning on this alias.
+namespace AliasWithSameName = Enclosing::Nested;
+
+namespace TestUsingDecls {
+
+namespace A {
+void foo();
+}
+namespace B {
+using A::foo; // <- a UsingDecl creating a UsingShadow
+}
+
+}// end namespace TestUsingDecls
+
+namespace TestUnresolvedTypenameAndValueDecls {
+
+template <class T> class Base;
+template <class T> class Derived : public Base<T> {
+public:
+  using typename Base<T>::foo;
+  using Base<T>::bar;
+  typedef typename Derived::foo NewUnresolvedUsingType;
+};
+
+} // end namespace TestUnresolvedTypenameAndValueDecls
+
+namespace TestUsingNamespace {
+  using namespace Enclosing;
+}