app-text/enscript: fix compilation for musl + gcc15

These compilation errors didn't appear before, because the buggy code is
only compiled and linked with musl.

The old Autotools included with enscript assume that, if you don't have
GLIBC, you can't link it with external gettext libraries, and it must use
the included gettext/libintl code.

Signed-off-by: Cristian Othón Martínez Vera <cfuga@cfuga.mx>
Part-of: https://github.com/gentoo/gentoo/pull/45577
Closes: https://github.com/gentoo/gentoo/pull/45577
Signed-off-by: Sam James <sam@gentoo.org>

app-text/enscript/enscript-1.6.6-r2.ebuild

@@ -28,6 +28,7 @@ PATCHES=(
 	"${FILESDIR}"/${PN}-1.6.4-fsf-gcc-darwin.patch
 	"${FILESDIR}"/${PN}-1.6.2-implicit-function-decl.patch
 	"${FILESDIR}"/${PN}-1.6.6-gcc15.patch
+	"${FILESDIR}"/${PN}-1.6.6-musl.patch
 )
 
 src_prepare() {

app-text/enscript/files/enscript-1.6.6-musl.patch

@@ -0,0 +1,39 @@
+--- a/intl/dcigettext.c
++++ b/intl/dcigettext.c
+@@ -152,7 +152,7 @@
+ #  if VMS
+ #   define getcwd(buf, max) (getcwd) (buf, max, 0)
+ #  else
+-char *getcwd ();
++char *getcwd (char *buf, size_t size);
+ #  endif
+ # endif
+ # ifndef HAVE_STPCPY
+--- a/compat/getopt.c
++++ b/compat/getopt.c
+@@ -210,7 +210,7 @@
+ /* Avoid depending on library functions or files
+    whose names are inconsistent.  */
+ 
+-char *getenv ();
++char *getenv (const char *name);
+ 
+ static char *
+ my_index (str, chr)
+--- a/compat/getopt.h
++++ b/compat/getopt.h
+@@ -99,14 +99,7 @@
+ #define optional_argument	2
+ 
+ #if defined (__STDC__) && __STDC__
+-#ifdef __GNU_LIBRARY__
+-/* Many other libraries have conflicting prototypes for getopt, with
+-   differences in the consts, in stdlib.h.  To avoid compilation
+-   errors, only prototype getopt for the GNU C library.  */
+ extern int getopt (int argc, char *const *argv, const char *shortopts);
+-#else /* not __GNU_LIBRARY__ */
+-extern int getopt ();
+-#endif /* __GNU_LIBRARY__ */
+ extern int getopt_long (int argc, char *const *argv, const char *shortopts,
+ 		        const struct option *longopts, int *longind);
+ extern int getopt_long_only (int argc, char *const *argv,