Lowercase configuration arguments on VMS

Depending on user preferences, Configure might get something like
--PREFIX=blah just as well as --prefix=blah, or "SHARED" just as well
as "shared".  On VMS, let's therefore lowercase at least the portion
of the argument before a possible equal sign.

For good measure, we lowercase the arguments to be checked in
config.com as well.  The original argument is sent on to Configure,
however.

Reviewed-by: Andy Polyakov <[email protected]>

Configure

@@ -501,6 +501,13 @@ $config{perlargv} = [ @argvcopy ];
 my %unsupported_options = ();
 foreach (@argvcopy)
 	{
+	# VMS is a case insensitive environment, and depending on settings
+	# out of our control, we may receive options uppercased.  Let's
+	# downcase at least the part before any equal sign.
+	if ($^O eq "VMS")
+		{
+		s/^([^=]*)/lc($1)/e;
+		}
 	s /^-no-/no-/; # some people just can't read the instructions
 
 	# rewrite some options in "enable-..." form

config.com

@@ -17,24 +17,24 @@ $	P_index = 0
 $	LOOP1:
 $	    P_index = P_index + 1
 $	    IF P_index .GT. 8 THEN GOTO ENDLOOP1
-$	    P1 = F$EDIT(P1,"TRIM")
-$	    IF P1 .EQS. "HELP" THEN GOTO USAGE
-$	    IF P1 .EQS. "32"
+$	    P = F$EDIT(P1,"TRIM,LOWERCASE")
+$	    IF P .EQS. "help" THEN GOTO USAGE
+$	    IF P .EQS. "32"
 $	    THEN
 $		pointer_size = "-P32"
-$		P1 = ""
+$		P = ""
 $	    ENDIF
-$	    IF P1 .EQS. "64"
+$	    IF P .EQS. "64"
 $	    THEN
 $		pointer_size = "-P64"
-$		P1 = ""
+$		P = ""
 $	    ENDIF
-$	    IF P1 .EQS. "DEBUG"
+$	    IF P .EQS. "debug"
 $	    THEN
 $		debug = "--debug"
-$		P1 = ""
+$		P = ""
 $	    ENDIF
-$	    IF P1 .NES. "" THEN -
+$	    IF P .NES. "" THEN -
 	       collected_args = collected_args + " " + P1
 $	    P1 = P2
 $	    P2 = P3