Merging r196724:

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r196724 | tnorthover | 2013-12-08 07:24:55 -0800 (Sun, 08 Dec 2013) | 5 lines

ARM: teach Sema that "r" can match 64-bit values

We already support using "r" on 64-bit values (a GPRPair is
allocated), but Sema doesn't know this yet so issues a warning. This
should fix it.
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llvm-svn: 196746