Fix a warning about comparison between signed and unsigned,
being consistent with the rest of the APInt implementation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47138 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index c8482e9..9886de8 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -818,7 +818,7 @@
     return std::min(uint32_t(CountTrailingOnes_64(VAL)), BitWidth);
   uint32_t Count = 0;
   uint32_t i = 0;
-  for (; i < getNumWords() && pVal[i] == -1; ++i)
+  for (; i < getNumWords() && pVal[i] == -1ULL; ++i)
     Count += APINT_BITS_PER_WORD;
   if (i < getNumWords())
     Count += CountTrailingOnes_64(pVal[i]);