scripts: fix compilation errors on darwin
    
    Add deprecated functions that are removed in darwin headers when
    _POSIX_C_SOURCE >= 200809L, `bcmp` and `strcasecmp`.
    
    Add `strset` that is defined when _POSIX_C_SOURCE >= __DARWIN_C_FULL,
    which unfortunately also brings in an incompatible definition of `uuid_t`.

diff --git a/scripts/dtc/dtc.c b/scripts/dtc/dtc.c
index bc786c543..f4e0ec483 100644
--- a/scripts/dtc/dtc.c
+++ b/scripts/dtc/dtc.c
@@ -8,6 +8,8 @@
 #include "dtc.h"
 #include "srcpos.h"
 
+int strcasecmp(const char *s1, const char *s2);
+
 /*
  * Command line options
  */
diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c
index f5dfdb9d8..28922de4d 100644
--- a/scripts/genksyms/genksyms.c
+++ b/scripts/genksyms/genksyms.c
@@ -10,6 +10,7 @@
 
  */
 
+#include <alloca.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 992575f1e..2b2fd5aa7 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -20,6 +20,8 @@
 
 #include "lkc.h"
 
+int bcmp(const void *b1, const void *b2, size_t len);
+
 /* return true if 'path' exists, false otherwise */
 static bool is_present(const char *path)
 {
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 2c80da022..dd087eb7d 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -23,6 +23,8 @@
 #include "modpost.h"
 #include "../../include/linux/license.h"
 
+char *strsep(char **stringp, const char *delim);
+
 /* Are we using CONFIG_MODVERSIONS? */
 static bool modversions;
 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c
index 6bf9caca0..f25f4c783 100644
--- a/scripts/mod/sumversion.c
+++ b/scripts/mod/sumversion.c
@@ -10,6 +10,8 @@
 #include <limits.h>
 #include "modpost.h"
 
+char *strsep(char **stringp, const char *delim);
+
 /*
  * Stolen form Cryptographic API.
  *