[PATCH] [AArch64] Fix a bug generating incorrect instruction when building small vector.

[Chad Rosier]

Tim should probably give the final LGTM, but I don't see any glaring issues.  I'll kick of regression tests and let you know how it goes.

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Comment at: lib/Target/AArch64/AArch64ISelLowering.cpp:4160
@@ -4160,1 +4159,3 @@
   int OffsetMultipliers[2] = { 1, 1 };
+  int ResMultipliers = 1;
+  // Find out the smallest element size among result and two sources, and use
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Perhaps, just ResMultiplier.

http://reviews.llvm.org/D4385