Remove unnecessary include

Between 6eeb95f0f56bb5e8a0a9328aeec04c9e6de87272 and
7b1c2a0f2066672b24f6257ec9b8d78a1754f494, builtins.h contained
additional prototypes that have now been moved elsewhere, so we don't
need to include nodes/parsenodes.h anymore.

Fix some files that were relying on builtins.h implicitly pulling in
some unrelated stuff they needed.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>

src/backend/catalog/pg_enum.c

@@ -24,6 +24,7 @@
 #include "catalog/pg_type.h"
 #include "storage/lmgr.h"
 #include "miscadmin.h"
+#include "nodes/value.h"
 #include "utils/builtins.h"
 #include "utils/catcache.h"
 #include "utils/fmgroids.h"

src/backend/utils/adt/oid.c

@@ -19,6 +19,7 @@
 
 #include "catalog/pg_type.h"
 #include "libpq/pqformat.h"
+#include "nodes/value.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 

src/include/utils/builtins.h

@@ -15,7 +15,6 @@
 #define BUILTINS_H
 
 #include "fmgr.h"
-#include "nodes/parsenodes.h"
 #include "utils/sortsupport.h"
 
 /*