diff: fix for GNU Make 3.76

[Fergus Henderson]

scripts/Mmake.vars.in:
	Set GPATH to the same value as VPATH.
	This is necessary to make things work with GNU Make versions >= 3.76.
	(Otherwise GNU Make tries to build the library interface files in
	the current directory rather than the library directory,
	if they are out-of-date with respect to the datestamp files,
	and then since they don't exist in the current directory,
	it thinks they have changed, even if they haven't.)

Index: scripts/Mmake.vars.in
===================================================================
RCS file: /home/staff/zs/imp/mercury/scripts/Mmake.vars.in,v
retrieving revision 1.9
diff -u -u -r1.9 Mmake.vars.in
--- Mmake.vars.in	1997/07/27 15:09:27	1.9
+++ Mmake.vars.in	1997/10/18 17:02:29
@@ -13,11 +13,14 @@
 # Ensure that commands use /bin/sh not the user's shell
 SHELL		= /bin/sh
 
+# Set the directory search path. 
+# (See the GNU Make manual for documentation about VPATH and GPATH.)
 MMAKE_VPATH	= $(MERCURY_INT_DIR)
 VPATH		= $(MMAKE_VPATH) # do not remove the `:' from this comment!!!
 #			 the above comment works around a misfeature of
 #			 autoconf which causes it to delete assignments to
 #			 VPATH unless they contain a `:'
+GPATH		= $(VPATH)
 
 DEFAULT_GRADE	= $(MERCURY_DEFAULT_GRADE)
 GRADE		= $(DEFAULT_GRADE)
-- 
Fergus Henderson <fjh at cs.mu.oz.au>   |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3         |     -- the last words of T. S. Garp.