Fix read of uninitialized enum value in test, caught by UBSan. No functionality
change, other than removal of undefined behavior.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187465 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReaderStmt.cpp b/lib/Serialization/ASTReaderStmt.cpp
index ed07b05..8cf4bae 100644
--- a/lib/Serialization/ASTReaderStmt.cpp
+++ b/lib/Serialization/ASTReaderStmt.cpp
@@ -1739,6 +1739,8 @@
 
 Stmt *ASTReader::ReadStmt(ModuleFile &F) {
   switch (ReadingKind) {
+  case Read_None:
+    llvm_unreachable("should not call this when not reading anything");
   case Read_Decl:
   case Read_Type:
     return ReadStmtFromStream(F);