Diagnostics improvements for 3.9

[Hans Wennborg via cfe-commits]

These all sgtm for 3.9. Go ahead and merge with
utils/release/merge.sh, or I'll do it when I get in on Monday.

Cheers,
Hans

On Fri, Aug 5, 2016 at 6:52 PM, Richard Trieu <rtrieu at google.com> wrote:
> Typos and unused test variables fixed in r277900
>
> On Fri, Aug 5, 2016 at 6:46 PM, Richard Smith <richard at metafoo.co.uk> wrote:
>>
>> On Fri, Aug 5, 2016 at 6:33 PM, Richard Smith <richard at metafoo.co.uk>
>> wrote:
>>>
>>> These all look OK for the branch. Hans, the second one fixes a crasher,
>>> so I'd like to take at least that one. The others fix warning false
>>> positives (which are not regressions) and look fairly safe.
>>
>>
>> Correction: looks like the final one is in fact a fix for a diagnostic
>> regression.
>>
>>>
>>> On Fri, Aug 5, 2016 at 4:39 PM, Richard Trieu <rtrieu at google.com> wrote:
>>>>
>>>> Hans, Richard,
>>>>
>>>> These are some last minute diagnostic improvements for 3.9.
>>>>
>>>> http://llvm.org/viewvc/llvm-project?rev=277796&view=rev
>>>> r277796
>>>> Don't warn when negative values, like -1, are used to initialize
>>>> unsigned bit fields.
>>>>
>>>> http://llvm.org/viewvc/llvm-project?rev=277797&view=rev
>>>> r277797
>>>> Fix crash with type alias in Template Type Diffing
>>>
>>>
>>> (You have a typo Internalal in this.)
>>>
>>>>
>>>> http://llvm.org/viewvc/llvm-project?rev=277866&view=rev
>>>> r277866
>>>> Fix false positive in -Wunsequenced and templates
>>>>
>>>> http://llvm.org/viewvc/llvm-project?rev=277889&view=rev
>>>> r277889
>>>> Fixes for two false positives in -Wreturn-stack-address dealing with
>>>> parameter variables and reference to pointer types.
>>>
>>>
>>> (Test has some x3 variables that are unused.)
>>
>>
>