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/WORKSPACE b/WORKSPACE
index aab671f..3e04fb1 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -1732,3 +1732,10 @@
 load("@com_github_storypku_bazel_iwyu//bazel:dependencies.bzl", "bazel_iwyu_dependencies")
 
 bazel_iwyu_dependencies()
+
+http_archive(
+    name = "m4_v1.4.18",
+    build_file = "@//debian:m4.BUILD",
+    sha256 = "ee8dfe664ac8c1d066bab64f71bd076a021875581b3cc47dac4a14a475f50b15",
+    url = "http://software.frc971.org/Build-Dependencies/m4.tar.gz",
+)