Summary:
Before this PR, `modernize-use-using` would transform the typedef in
```
template <typename a> class TemplateKeyword {
typedef typename a::template f<> e;
typedef typename a::template f<>::d e2;
};
```
into
```
template <typename a> class TemplateKeyword {
using d = typename a::b<>;
using d2 = typename a::template a::b<>::c;
};
```
The first one is missing the `template` keyword,
the second one has an extra `a::` scope. Both result
in compilation errors.
Reviewers: aaron.ballman, alexfh, hokein, njames93
Subscribers: xazax.hun, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D78139