add FXdiv (#48)

Summary:
Pull Request resolved: #48

adding FX div submodule under xnnpack/third-party. This is because XNNPACK uses FXdiv as a dependency.

Reviewed By: digantdesai

Differential Revision: D48180547

fbshipit-source-id: 1f4947111aad33a7f72040063f93dbc68f84f0eb

Author: mcr229

.gitmodules

@@ -19,3 +19,6 @@
 [submodule "backends/xnnpack/third-party/FP16"]
 	path = backends/xnnpack/third-party/FP16
 	url = https://github.com/Maratyszcza/FP16.git
+[submodule "backends/xnnpack/third-party/FXdiv"]
+	path = backends/xnnpack/third-party/FXdiv
+	url = https://github.com/Maratyszcza/FXdiv.git

backends/xnnpack/third-party/FXdiv

@@ -16,3 +16,12 @@ native.cxx_library(
     force_static = True,
     visibility = ["PUBLIC"],
 )
+
+native.cxx_library(
+    name = "FXdiv",
+    header_namespace = "",
+    exported_headers = {
+        "fxdiv.h": "FXdiv/include/fxdiv.h",
+    },
+    visibility = ["PUBLIC"],
+)