Fix typo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79688 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index 2d8df5e..d50e4e5 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -2740,7 +2740,7 @@
   words[0] = mysignificand;
   words[1] = ((uint64_t)(sign & 1) << 63) |
              ((myexponent & 0x7fff) << 48) |
-             (mysignificand & 0xffffffffffffLL);
+             (mysignificand2 & 0xffffffffffffLL);
 
   return APInt(128, 2, words);
 }