[CWG400](https://wg21.link/cwg400) rejects member using-declaration
whose nested-name-specifier doesn't refer to a base class of the current
class.
```cpp
struct A {};
struct B {
using B::A; // error
};
```
Clang didn't reject this case in C++98 mode. This patch fixes this
issue.
This clears up the printing of a NestedNameSpecifier so a trailing '::'
is not printed, unless it refers into the global scope.
This fixes a bunch of diagnostics where the trailing :: was awkward.
This also prints the NNS quoted consistenty.
There is a drive-by improvement to error recovery, where now we print
the actual type instead of `<dependent type>`.
This will clear up further uses of NNS printing in further patches.
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
is difficult because they're so terribly, terribly ambiguous.
We implement access declarations in terms of using declarations, which is
quite reasonable. However, we should really persist the access/using
distinction in the AST and use the appropriate name in diagnostics. This
isn't a priority, so I'll just file a PR and hope someone else does it. :)
llvm-svn: 91095
