_GNU_SOURCE redundant define

[Greg Troxel]

On NetBSD-current/amd64, the branch_release-1-8 branch fails to build.
_GNU_SOURCE is defined in config.h, and also in two files.  With the
following change, it builds and 'gmake check' succeeds.

I'm not sure why _GNU_SOURCE is there; it seems guile should be mostly
relying on POSIX-specified things.  Clearly it at least mostly is, or it
wouldn't build on NetBSD, which doesn't use GNU libc.

diff --git a/libguile/posix.c b/libguile/posix.c
index e803f9f..c4570af 100644
--- a/libguile/posix.c
+++ b/libguile/posix.c
@@ -21,9 +21,6 @@
 #  include <config.h>
 #endif
 
-/* Make GNU/Linux libc declare everything it has. */
-#define _GNU_SOURCE
-
 #include <stdio.h>
 #include <errno.h>
 
diff --git a/libguile/srfi-14.c b/libguile/srfi-14.c
index f61db7d..69e7798 100644
--- a/libguile/srfi-14.c
+++ b/libguile/srfi-14.c
@@ -21,9 +21,6 @@
 #  include <config.h>
 #endif
 
-
-#define _GNU_SOURCE  /* Ask for `isblank ()'.  */
-
 #include <string.h>
 #include <ctype.h>


failing log at:

http://autobuild.josefsson.org/guile/log-200808131846090405000.txt

(thanks to ludo for help setting up for autobuilding)