Update the upsert parsing so that it accepts conflict-target labels using
the PostgreSQL syntax, and also accepts the MySQL "ON DUPLICATE KEY"
syntax.

FossilOrigin-Name: c48f64d8ae2625a19267b02e4a173a07766934235ad3052cd9d38f5ecbcbfbc3
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index d77df3e..1be52c2 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -4270,11 +4270,13 @@
 #define sqlite3WithDelete(x,y)
 #endif
 #ifndef SQLITE_OMIT_UPSERT
+  Upsert *sqlite3UpsertNew(sqlite3*,Upsert*,ExprList*,ExprList*);
   void sqlite3UpsertDelete(sqlite3*,Upsert*);
   Upsert *sqlite3UpsertDup(sqlite3*,Upsert*);
 #else
+#define sqlite3UpsertNew(x,y,z)   ((Upsert*)0)
 #define sqlite3UpsertDelete(x,y)
-#define sqlite3UpsertDup(x,y) ((Upsert*)0)
+#define sqlite3UpsertDup(x,y)     ((Upsert*)0)
 #endif