Support ObjC implementation decls for PCH.

Strictly speaking, implementations don't go in headers but there's no law against it.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110567 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/PCH/objcxx-ivar-class.h b/test/PCH/objcxx-ivar-class.h
new file mode 100644
index 0000000..aa114e5
--- /dev/null
+++ b/test/PCH/objcxx-ivar-class.h
@@ -0,0 +1,11 @@
+struct S {
+    S();
+};
+
+@interface C {
+    S s;
+}
+@end
+
+@implementation C
+@end