Silence static analyzer getAs<RecordType> null dereference warnings. NFCI.

The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<RecordType> directly and if not assert will fire for us.

llvm-svn: 373584
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 71d99bc..576d1b6 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1699,7 +1699,7 @@
   const ASTRecordLayout &RL = CGM.getContext().getASTRecordLayout(RD);
   for (const auto &BI : Bases) {
     const auto *Base =
-        cast<CXXRecordDecl>(BI.getType()->getAs<RecordType>()->getDecl());
+        cast<CXXRecordDecl>(BI.getType()->castAs<RecordType>()->getDecl());
     if (!SeenTypes.insert(Base).second)
       continue;
     auto *BaseTy = getOrCreateType(BI.getType(), Unit);