[Sparc]: correct the ATOMIC_LLONG_LOCK_FREE macro

[dougk]

fix atomics-inlining test

lib/Basic/Targets.cpp

       PtrDiffType = SignedLong;
       break;
     }
-    MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 64;
+    // Up to 32 bits are lock-free atomic, but we're willing to do atomic ops
+    // on up to 64 bits.
+    MaxAtomicPromoteWidth = 64;
+    MaxAtomicInlineWidth = 32;
   }
 
   void getTargetDefines(const LangOptions &Opts,

test/Preprocessor/init.c

 // SPARC:#define __FLT_MIN_EXP__ (-125)
 // SPARC:#define __FLT_MIN__ 1.17549435e-38F
 // SPARC:#define __FLT_RADIX__ 2
+// SPARC:#define __GCC_ATOMIC_LLONG_LOCK_FREE 1
 // SPARC:#define __INT16_C_SUFFIX__
 // SPARC:#define __INT16_FMTd__ "hd"
 // SPARC:#define __INT16_FMTi__ "hi"