Centralize error reporting of improper uses of incomplete types in the
new DiagnoseIncompleteType. It provides additional information about
struct/class/union/enum types when possible, either by pointing to the
forward declaration of that type or by pointing to the definition (if
we're in the process of defining that type). 
Fixes <rdar://problem/6500531>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62521 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Parser/recovery.c b/test/Parser/recovery.c
index 430d3c1..b6ba9e6 100644
--- a/test/Parser/recovery.c
+++ b/test/Parser/recovery.c
@@ -65,6 +65,6 @@
   [10]  // expected-error {{expected expression}}
 }
 
-struct forward;
+struct forward; // expected-note{{forward declaration of 'struct forward'}}
 void x(struct forward* x) {switch(x->a) {}} // expected-error {{incomplete definition of type}}