Implement IntervalMap::clear().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119872 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/ADT/IntervalMapTest.cpp b/unittests/ADT/IntervalMapTest.cpp
index c7def84..d4b2f52b 100644
--- a/unittests/ADT/IntervalMapTest.cpp
+++ b/unittests/ADT/IntervalMapTest.cpp
@@ -315,6 +315,11 @@
   EXPECT_EQ(320u, I.stop());
   ++I;
   EXPECT_FALSE(I.valid());
+
+  // Test clear() on non-branched map.
+  map.clear();
+  EXPECT_TRUE(map.empty());
+  EXPECT_TRUE(map.begin() == map.end());
 }
 
 // Branched, non-coalescing tests.
@@ -362,6 +367,10 @@
   }
   EXPECT_TRUE(I == map.begin());
 
+  // Test clear() on branched map.
+  map.clear();
+  EXPECT_TRUE(map.empty());
+  EXPECT_TRUE(map.begin() == map.end());
 }
 
 } // namespace