Remove pgrminclude and associated scripts

Per git log, the last time someone tried to do something with
pgrminclude was around 2011.  And it's always had a tendency of
causing trouble when it was active.  Also, pgcominclude is redundant
with headerscheck.

Discussion: https://www.postgresql.org/message-id/flat/2d4dc7b2-cb2e-49b1-b8ca-ba5f7024f05b%40eisentraut.org

Author: petere

src/tools/pginclude/README

@@ -1,68 +1,5 @@
 src/tools/pginclude/README
 
-NOTE: headerscheck and headerscheck --cplusplus are in current use,
-and any problems they find should generally get fixed.  The other
-scripts in this directory have not been used in some time, and have
-issues.  pgrminclude in particular has a history of creating more
-problems than it fixes.  Be very wary of applying their results
-blindly.
-
-
-pginclude
-=========
-
-These utilities help clean up #include file usage.  They should be run
-in this order so that the include files have the proper includes before
-the C files are tested.
-
-pgfixinclude	change #include's to <> or ""
-
-pgcompinclude [-v]
-		report which #include files can not compile on their own
-
-pgrminclude [-v]
-		remove extra #include's
-
-pgcheckdefines
-		check for #ifdef tests on symbols defined in files that
-		weren't included --- this is a necessary sanity check on
-		pgrminclude
-
-pgdefine	create macro calls for all defines in the file (used by
-		the above routines)
-
-It is also a good idea to sort the pg-specific include files in
-alphabetic order.  This is best done with a text editor. Typical usage
-order would be:
-
-	pgfixinclude
-	sort include references
-	run multiple times:
-		pgcompinclude
-		pgrminclude /src/include
-	pgrminclude /
-	pgcheckdefines
-
-There is a complexity when modifying /src/include.  If include file 1
-includes file 2, and file 2 includes file 3, then when file 1 is
-processed, it needs only file 2, not file 3.  However, if later, include
-file 2 is processed, and file 3 is not needed by file 2 and is removed,
-file 1 might then need to include file 3.  For this reason, the
-pgcompinclude and pgrminclude /src/include steps must be run several
-times until all includes compile cleanly.
-
-Also, tests should be done with configure settings of --enable-cassert
-and EXEC_BACKEND on and off.  It is also wise to test a WIN32 compile.
-
-Another tools that does a similar task is at:
-
-	http://code.google.com/p/include-what-you-use/
-
-An include file visualizer script is available at:
-
-	http://archives.postgresql.org/pgsql-hackers/2011-09/msg00311.php
-
-
 headerscheck
 ============