Provide mprotect syscall

sysdeps/nacl/irt.h

Index: sysdeps/nacl/irt.h
diff --git a/sysdeps/nacl/irt.h b/sysdeps/nacl/irt.h
index c363d032da8aafaf02b7466ee4e52ce466419dea..300ae8e43f35c9772205d7c740e7d3c27b53da75 100644
--- a/sysdeps/nacl/irt.h
+++ b/sysdeps/nacl/irt.h
@@ -78,12 +78,20 @@ struct nacl_irt_filename {
 };
 
 #define NACL_IRT_MEMORY_v0_1    "nacl-irt-memory-0.1"
-struct nacl_irt_memory {
+struct nacl_irt_memory_v0_1 {
   int (*sysbrk)(void **newbrk);
   int (*mmap)(void **addr, size_t len, int prot, int flags, int fd, off_t off);
   int (*munmap)(void *addr, size_t len);
 };
 
+#define NACL_IRT_MEMORY_v0_2    "nacl-irt-memory-0.2"
+struct nacl_irt_memory_v0_2 {
+  int (*sysbrk)(void **newbrk);
+  int (*mmap)(void **addr, size_t len, int prot, int flags, int fd, off_t off);
+  int (*munmap)(void *addr, size_t len);
+  int (*mprotect)(void *addr, size_t len, int prot);
+};
+
 #define NACL_IRT_DYNCODE_v0_1   "nacl-irt-dyncode-0.1"
 struct nacl_irt_dyncode {
   int (*dyncode_create)(void *dest, const void *src, size_t size);