[llvm] r216821 - Add a test for converting ArrayRef<T *> to ArrayRef<const T *>.

[Duncan P. N. Exon Smith]

> On 2014 Aug 30, at 22:05, Craig Topper <craig.topper at gmail.com> wrote:
> 
> Thanks! I think only cv qualifiers will be allowed at least based on my understanding of is_convertible.

In this context I believe you're correct.  Generally
`is_convertible` succeeds whenever implicit conversion between
types is valid.  There are some surprising cases where `is_same`
does not imply `is_convertible`.