[Msan] Fix the ifaddrs.cc test to build and pass on FreeBSD

[samsonov]

LGTM

compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h

#define SANITIZER_INTERCEPT_PTHREAD_SETNAME_NP \
   SI_FREEBSD || SI_LINUX_NOT_ANDROID
 
 #define SANITIZER_INTERCEPT_TLS_GET_ADDR \
   SI_FREEBSD || SI_LINUX_NOT_ANDROID
 
 #define SANITIZER_INTERCEPT_LISTXATTR SI_LINUX
 #define SANITIZER_INTERCEPT_GETXATTR SI_LINUX
 #define SANITIZER_INTERCEPT_GETRESID SI_LINUX
-#define SANITIZER_INTERCEPT_GETIFADDRS SI_LINUX_NOT_ANDROID || SI_MAC
+#define SANITIZER_INTERCEPT_GETIFADDRS \
+  SI_FREEBSD || SI_LINUX_NOT_ANDROID || SI_MAC
 #define SANITIZER_INTERCEPT_IF_INDEXTONAME SI_LINUX_NOT_ANDROID || SI_MAC
 #define SANITIZER_INTERCEPT_CAPGET SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_AEABI_MEM SI_LINUX && defined(__arm__)
 #define SANITIZER_INTERCEPT___BZERO SI_MAC
 #define SANITIZER_INTERCEPT_FTIME !SI_FREEBSD && SI_NOT_WINDOWS
 #define SANITIZER_INTERCEPT_XDR SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_TSEARCH SI_LINUX_NOT_ANDROID || SI_MAC
 #define SANITIZER_INTERCEPT_LIBIO_INTERNALS SI_LINUX_NOT_ANDROID

compiler-rt/trunk/test/msan/ifaddrs.cc

 // RUN: %clangxx_msan -O0 %s -o %t && %run %t %p 2>&1
 // RUN: %clangxx_msan -O0 -D_FILE_OFFSET_BITS=64 %s -o %t && %run %t %p 2>&1
 // RUN: %clangxx_msan -O3 %s -o %t && %run %t %p 2>&1
 
 #include <assert.h>
 #include <errno.h>
 #include <ifaddrs.h>
 #include <stdio.h>
 #include <string.h>
 
 #include <vector>
 
+#if defined(__FreeBSD__)
+#include <sys/socket.h>  // To define 'struct sockaddr'.
+#endif
+
 #include <sanitizer/msan_interface.h>
 
 #define CHECK_AND_PUSH(addr, size)                                \
   if (addr) {                                                     \
     assert(-1 == __msan_test_shadow(addr, sizeof(size)));         \
     ranges.push_back(std::make_pair((void *)addr, (size_t)size)); \
   }