[libFuzzer] Use long long to ensure 64 bits.

We should always use unsigned long long to ensure 64 bits. On Windows, unsigned
long is 4 bytes. This was the reason why value-profile-cmp4.test was failing on
Windows.

Differential Revision: https://reviews.llvm.org/D29617

llvm-svn: 294390
diff --git a/llvm/lib/Fuzzer/FuzzerValueBitMap.h b/llvm/lib/Fuzzer/FuzzerValueBitMap.h
index 68dc3a9..600337a 100644
--- a/llvm/lib/Fuzzer/FuzzerValueBitMap.h
+++ b/llvm/lib/Fuzzer/FuzzerValueBitMap.h
@@ -68,7 +68,7 @@
         Other.Map[i] = 0;
       }
       if (M)
-        Res += __builtin_popcountl(M);
+        Res += __builtin_popcountll(M);
     }
     NumBits = Res;
     return OldNumBits < NumBits;