[mips64] Support for mips n64

Adding remaining mips n64 support including stackwalker.

BUG=None
TEST=manually tested on Linux/Android
R=vapier@chromium.org

Review URL: https://codereview.chromium.org/1418453011 .

src/common/android/include/sys/procfs.h

@@ -101,8 +101,8 @@ struct elf_prpsinfo {
   unsigned int   pr_uid;
   unsigned int   pr_gid;
 #elif defined(__mips__)
-  unsigned long  pr_uid;
-  unsigned long  pr_gid;
+  __kernel_uid_t pr_uid;
+  __kernel_gid_t pr_gid;
 #else
   unsigned short pr_uid;
   unsigned short pr_gid;