Handle contrib's GIN/GIST support function signature changes honestly.

In commits 9ff60273e3 and dbe2328959 I (tgl) fixed the
signatures of a bunch of contrib's GIN and GIST support functions so that
they would pass validation by the recently-added amvalidate functions.
The backend does not actually consult or check those signatures otherwise,
so I figured this was basically cosmetic and did not require an extension
version bump.  However, Alexander Korotkov pointed out that that would
leave us in a pretty messy situation if we ever wanted to redefine those
functions later, because there wouldn't be a unique way to name them.
Since we're going to be bumping these extensions' versions anyway for
parallel-query cleanups, let's take care of this now.

Andreas Karlsson, adjusted for more search-path-safety by me

contrib/hstore/Makefile

@@ -5,7 +5,7 @@ OBJS = hstore_io.o hstore_op.o hstore_gist.o hstore_gin.o hstore_compat.o \
 	$(WIN32RES)
 
 EXTENSION = hstore
-DATA = hstore--1.3.sql hstore--1.2--1.3.sql \
+DATA = hstore--1.4.sql hstore--1.3--1.4.sql hstore--1.2--1.3.sql \
 	hstore--1.1--1.2.sql hstore--1.0--1.1.sql \
 	hstore--unpackaged--1.0.sql
 PGFILEDESC = "hstore - key/value pair data type"

contrib/hstore/hstore--1.3--1.4.sql

@@ -0,0 +1,26 @@
+/* contrib/hstore/hstore--1.3--1.4.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION hstore UPDATE TO '1.4'" to load this file. \quit
+
+-- Update procedure signatures the hard way.
+-- We use to_regprocedure() so that query doesn't fail if run against 9.6beta1 definitions,
+-- wherein the signatures have been updated already.  In that case to_regprocedure() will
+-- return NULL and no updates will happen.
+
+UPDATE pg_catalog.pg_proc SET
+  proargtypes = pg_catalog.array_to_string(newtypes::pg_catalog.oid[], ' ')::pg_catalog.oidvector,
+  pronargs = pg_catalog.array_length(newtypes, 1)
+FROM (VALUES
+(NULL::pg_catalog.text, NULL::pg_catalog.regtype[]), -- establish column types
+('ghstore_same(internal,internal,internal)', '{ghstore,ghstore,internal}'),
+('ghstore_consistent(internal,internal,int4,oid,internal)', '{internal,hstore,int2,oid,internal}'),
+('gin_extract_hstore(internal,internal)', '{hstore,internal}'),
+('gin_extract_hstore_query(internal,internal,int2,internal,internal)', '{hstore,internal,int2,internal,internal}'),
+('gin_consistent_hstore(internal,int2,internal,int4,internal,internal)', '{internal,int2,hstore,int4,internal,internal}')
+) AS update_data (oldproc, newtypes)
+WHERE oid = pg_catalog.to_regprocedure(oldproc);
+
+UPDATE pg_catalog.pg_proc SET
+  prorettype = 'ghstore'::pg_catalog.regtype
+WHERE oid = pg_catalog.to_regprocedure('ghstore_union(internal,internal)');

contrib/hstore/hstore--1.4.sql

@@ -1,4 +1,4 @@
-/* contrib/hstore/hstore--1.3.sql */
+/* contrib/hstore/hstore--1.4.sql */
 
 -- complain if script is sourced in psql, rather than via CREATE EXTENSION
 \echo Use "CREATE EXTENSION hstore" to load this file. \quit

contrib/hstore/hstore.control

@@ -1,5 +1,5 @@
 # hstore extension
 comment = 'data type for storing sets of (key, value) pairs'
-default_version = '1.3'
+default_version = '1.4'
 module_pathname = '$libdir/hstore'
 relocatable = true