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/seg/Makefile

@@ -4,7 +4,7 @@ MODULE_big = seg
 OBJS = seg.o segparse.o $(WIN32RES)
 
 EXTENSION = seg
-DATA = seg--1.0.sql seg--unpackaged--1.0.sql
+DATA = seg--1.1.sql seg--1.0--1.1.sql seg--unpackaged--1.0.sql
 PGFILEDESC = "seg - line segment data type"
 
 REGRESS = seg

contrib/seg/seg--1.0--1.1.sql

@@ -0,0 +1,18 @@
+/* contrib/seg/seg--1.0--1.1.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION seg UPDATE TO '1.1'" 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
+('gseg_consistent(internal,seg,int4,oid,internal)', '{internal,seg,int2,oid,internal}')
+) AS update_data (oldproc, newtypes)
+WHERE oid = pg_catalog.to_regprocedure(oldproc);

contrib/seg/seg--1.1.sql

@@ -1,4 +1,4 @@
-/* contrib/seg/seg--1.0.sql */
+/* contrib/seg/seg--1.1.sql */
 
 -- complain if script is sourced in psql, rather than via CREATE EXTENSION
 \echo Use "CREATE EXTENSION seg" to load this file. \quit

contrib/seg/seg.control

@@ -1,5 +1,5 @@
 # seg extension
 comment = 'data type for representing line segments or floating-point intervals'
-default_version = '1.0'
+default_version = '1.1'
 module_pathname = '$libdir/seg'
 relocatable = true