Add null-check assertion in the constructor of Selector.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66290 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/IdentifierTable.h b/include/clang/Basic/IdentifierTable.h
index 32818a9..5c84203 100644
--- a/include/clang/Basic/IdentifierTable.h
+++ b/include/clang/Basic/IdentifierTable.h
@@ -344,6 +344,7 @@
   
   Selector(IdentifierInfo *II, unsigned nArgs) {
     InfoPtr = reinterpret_cast<uintptr_t>(II);
+    assert(II && "Null IdentifierInfo passed to Selector constructor.");
     assert((InfoPtr & ArgFlags) == 0 &&"Insufficiently aligned IdentifierInfo");
     assert(nArgs < 2 && "nArgs not equal to 0/1");
     InfoPtr |= nArgs+1;