Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/ADT/StringMap.h b/linux-x64/clang/include/llvm/ADT/StringMap.h
index d34d5ed..a9f83d3 100644
--- a/linux-x64/clang/include/llvm/ADT/StringMap.h
+++ b/linux-x64/clang/include/llvm/ADT/StringMap.h
@@ -164,9 +164,7 @@
 
     StringMapEntry *NewItem =
       static_cast<StringMapEntry*>(Allocator.Allocate(AllocSize,Alignment));
-
-    if (NewItem == nullptr)
-      report_bad_alloc_error("Allocation of StringMap entry failed.");
+    assert(NewItem && "Unhandled out-of-memory");
 
     // Construct the value.
     new (NewItem) StringMapEntry(KeyLength, std::forward<InitTy>(InitVals)...);