Implement -Wunused-label.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@114315 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReaderStmt.cpp b/lib/Serialization/ASTReaderStmt.cpp
index 6e8ad4f..7b0845d 100644
--- a/lib/Serialization/ASTReaderStmt.cpp
+++ b/lib/Serialization/ASTReaderStmt.cpp
@@ -219,6 +219,7 @@
   S->setID(Reader.GetIdentifierInfo(Record, Idx));
   S->setSubStmt(Reader.ReadSubStmt());
   S->setIdentLoc(SourceLocation::getFromRawEncoding(Record[Idx++]));
+  S->setUsed(Record[Idx++]);
   Reader.RecordLabelStmt(S, Record[Idx++]);
 }