Revert "Remove gmp from AOS"

This reverts commit f37c97684f0910a3f241394549392f00145ab0f7.

We need gmp for SymEngine for symbolicmanipultion in C++

Change-Id: Ia13216d1715cf96944f7b4f422b7a799f921d4a4
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/third_party/gmp/mpz/cmp_ui.c b/third_party/gmp/mpz/cmp_ui.c
new file mode 100644
index 0000000..4b40ab7
--- /dev/null
+++ b/third_party/gmp/mpz/cmp_ui.c
@@ -0,0 +1,77 @@
+/* mpz_cmp_ui.c -- Compare an mpz_t a with an mp_limb_t b.  Return positive,
+  zero, or negative based on if a > b, a == b, or a < b.
+
+Copyright 1991, 1993-1996, 2001, 2002 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of either:
+
+  * the GNU Lesser General Public License as published by the Free
+    Software Foundation; either version 3 of the License, or (at your
+    option) any later version.
+
+or
+
+  * the GNU General Public License as published by the Free Software
+    Foundation; either version 2 of the License, or (at your option) any
+    later version.
+
+or both in parallel, as here.
+
+The GNU MP Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library.  If not,
+see https://www.gnu.org/licenses/.  */
+
+#include "gmp-impl.h"
+
+int
+_mpz_cmp_ui (mpz_srcptr u, unsigned long int v_digit) __GMP_NOTHROW
+{
+  mp_ptr up;
+  mp_size_t un;
+  mp_limb_t ul;
+
+  up = PTR(u);
+  un = SIZ(u);
+
+  if (un == 0)
+    return -(v_digit != 0);
+
+  if (un == 1)
+    {
+      ul = up[0];
+      if (ul > v_digit)
+	return 1;
+      if (ul < v_digit)
+	return -1;
+      return 0;
+    }
+
+#if GMP_NAIL_BITS != 0
+  if (v_digit > GMP_NUMB_MAX)
+    {
+      if (un == 2)
+	{
+	  ul = up[0] + (up[1] << GMP_NUMB_BITS);
+
+	  if ((up[1] >> GMP_NAIL_BITS) != 0)
+	    return 1;
+
+	  if (ul > v_digit)
+	    return 1;
+	  if (ul < v_digit)
+	    return -1;
+	  return 0;
+	}
+    }
+#endif
+
+  return un > 0 ? 1 : -1;
+}