Unbreak unit tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79879 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Support/ConstantRangeTest.cpp b/unittests/Support/ConstantRangeTest.cpp
index f377b6f..56f315a 100644
--- a/unittests/Support/ConstantRangeTest.cpp
+++ b/unittests/Support/ConstantRangeTest.cpp
@@ -16,6 +16,13 @@
 
 namespace {
 
+// Support APInt output to an std::ostream.
+inline std::ostream &operator<<(std::ostream &OS, const APInt &Value) {
+  raw_os_ostream RawOS(OS);
+  RawOS << Value;
+  return OS;
+}
+
 class ConstantRangeTest : public ::testing::Test {
 protected:
   static ConstantRange Full;