Switch client-side code to include catalog/pg_foo_d.h not pg_foo.h.

Everything of use to frontend code should now appear in the _d.h files,
and making this change frees us from needing to worry about whether the
catalog header files proper are frontend-safe.

Remove src/interfaces/ecpg/ecpglib/pg_type.h entirely, as the previous
commit reduced it to a confusingly-named wrapper around pg_type_d.h.

In passing, make test_rls_hooks.c follow project convention of including
our own files with #include "" not <>.

Discussion: https://postgr.es/m/23690.1523031777@sss.pgh.pa.us

src/interfaces/ecpg/ecpglib/descriptor.c

@@ -5,7 +5,8 @@
 
 #define POSTGRES_ECPG_INTERNAL
 #include "postgres_fe.h"
-#include "pg_type.h"
+
+#include "catalog/pg_type_d.h"
 
 #include "ecpg-pthread-win32.h"
 #include "ecpgtype.h"

src/interfaces/ecpg/ecpglib/execute.c

@@ -19,7 +19,7 @@
 #include <float.h>
 #include <math.h>
 
-#include "pg_type.h"
+#include "catalog/pg_type_d.h"
 
 #include "ecpgtype.h"
 #include "ecpglib.h"

src/interfaces/ecpg/ecpglib/pg_type.h

@@ -1,18 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * pg_type.h
- *	  Interface to generated type OID symbols.
- *
- * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * src/interfaces/ecpg/ecpglib/pg_type.h
- *
- *-------------------------------------------------------------------------
- */
-#ifndef PG_TYPE_H
-#define PG_TYPE_H
-
-#include "catalog/pg_type_d.h"
-
-#endif							/* PG_TYPE_H */

src/interfaces/ecpg/ecpglib/sqlda.c

@@ -8,7 +8,8 @@
 
 #define POSTGRES_ECPG_INTERNAL
 #include "postgres_fe.h"
-#include "pg_type.h"
+
+#include "catalog/pg_type_d.h"
 
 #include "ecpg-pthread-win32.h"
 #include "decimal.h"

src/interfaces/ecpg/ecpglib/typename.c

@@ -3,12 +3,13 @@
 #define POSTGRES_ECPG_INTERNAL
 #include "postgres_fe.h"
 
+#include "catalog/pg_type_d.h"
+
 #include "ecpgtype.h"
 #include "ecpglib.h"
 #include "extern.h"
 #include "sqltypes.h"
 #include "sql3types.h"
-#include "pg_type.h"
 
 /*
  * This function is used to generate the correct type names.