[LLVMdev] "equivalent" .ll files diverge after optimizations are applied

[Chris Lattner]

>>> Those types are all used with NEON.  I'll try to do some experiments to measure the impact of this....
>> 
>> If it matters, I can conditionalize the hack on the target triple being i386/x86-64.  Just let me know.
> 
> Some simple test programs look fine.
> 
> It also turns out that my nightly tester picked up this change last night.  I didn't see any obvious problems there except for a 13.5% regression on one internal test (<rdar://problem/8383253>) but that regression still reproduces with this change reverted.  I sure don't want that hack to stick around for long, but as long as it gets removed soon, I guess we're fine for now.

Just to be safe, I made this only kick in on x86: r112763

-Chris