[llvm] r278532 - ADT: Remove the ilist_nextprev_traits customization point

[Duncan P. N. Exon Smith via llvm-commits]

> On 2016-Aug-12, at 15:11, Hans Wennborg <hans at chromium.org> wrote:
> 
> On Fri, Aug 12, 2016 at 3:01 PM, Duncan P. N. Exon Smith
> <dexonsmith at apple.com> wrote:
>> 
>>> On 2016-Aug-12, at 14:48, Hans Wennborg <hans at chromium.org> wrote:
>>> 
>>> Just a heads up I'm getting compiler crashes building Chromium on
>>> Windows with this (well, r278539 really). Still not sure what's going
>>> on, though.. http://crbug.com/637413
>>> 
>>> It's crashing here:
>>> 
>>> void X86FrameLowering::emitEpilogue(MachineFunction &MF,
>>>                                   MachineBasicBlock &MBB) const {
>>> const MachineFrameInfo &MFI = MF.getFrameInfo();
>>> X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
>>> MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
>>> unsigned RetOpcode = MBBI->getOpcode();    <--- CRASH
>>> 
>>> 
>>> I assume MBBI is an ilist_iterator<> of some kind, but I still haven't
>>> been able to figure out what's up, or reproduce the crash on Linux :-/
>> 
>> Weird, I don't know why that would be caused by this commit.  Must affect the optimizer?
>> 
>> Should be reproducible on Linux by adding:
>> 
>>    assert(MBBI != MBB.end());
>> 
>> before using it.
> 
> Thanks! The assert fires on Linux, so now I'm in business :-)

Great!  Are you going to fix it too?  (Great if so (thanks!), but otherwise I should dig in myself.)