[rebranch] Add missing string include

bnbarham · bnbarham · commit 8e9999242f8e · 2021-11-16T23:46:47.000+10:00
diff --git a/include/swift/Demangling/TypeLookupError.h b/include/swift/Demangling/TypeLookupError.h
@@ -20,7 +20,7 @@
 
 #include "swift/Basic/TaggedUnion.h"
 #include "swift/Runtime/Portability.h"
-#include <string.h>
+#include <string>
 
 namespace swift {
 
