configure: Get rid of the check for strings.h.

configure

@@ -5896,7 +5896,6 @@ for ac_header in \
 	scsi/sg.h \
 	stdbool.h \
 	stdint.h \
-	strings.h \
 	stropts.h \
 	sys/asoundlib.h \
 	sys/attr.h \

configure.ac

@@ -483,7 +483,6 @@ AC_CHECK_HEADERS(\
 	scsi/sg.h \
 	stdbool.h \
 	stdint.h \
-	strings.h \
 	stropts.h \
 	sys/asoundlib.h \
 	sys/attr.h \

dlls/ntdll/serial.c

@@ -27,9 +27,6 @@
 #include <stdlib.h>
 #include <stdarg.h>
 #include <stdio.h>
-#ifdef HAVE_STRINGS_H
-# include <strings.h>
-#endif
 #ifdef HAVE_TERMIOS_H
 #include <termios.h>
 #endif

libs/port/getopt.c

@@ -203,22 +203,8 @@ static enum
 /* Value of POSIXLY_CORRECT environment variable.  */
 static char *posixly_correct;
 
-#ifdef	__GNU_LIBRARY__
-/* We want to avoid inclusion of string.h with non-GNU libraries
-   because there are many ways it can cause trouble.
-   On some systems, it contains special magic macros that don't work
-   in GCC.  */
-# include <string.h>
-# define my_index	strchr
-#else
-
-# ifdef HAVE_STRING_H
-#  include <string.h>
-# else
-#  include <strings.h>
-# endif
-
-# define my_index strchr
+#include <string.h>
+#define my_index strchr
 
 /* If using GCC, we can safely declare strlen this way.
    If not using GCC, it is ok not to declare it.  */
@@ -232,8 +218,6 @@ extern int strlen (const char *);
 # endif /* not __STDC__ */
 #endif /* __GNUC__ */
 
-#endif /* not __GNU_LIBRARY__ */
-
 /* Handle permutation of arguments.  */
 
 /* Describe the part of ARGV that contains non-options that have