Add support for building lmfit external library.

This multi-part change is composed of the following changes:

  I1e6b5ca0d248e60ffc099814e441dcaef06b8240
  Ife910862eb06425550c07046ad166767aa149401

Bug: 36445819
Test: Built Android and verified that lmfit builds successfully.
Change-Id: I1e6b5ca0d248e60ffc099814e441dcaef06b8240
diff --git a/Android.mk b/Android.mk
new file mode 100644
index 0000000..14cc2b9
--- /dev/null
+++ b/Android.mk
@@ -0,0 +1,28 @@
+# Copyright 2017 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    lib/lmcurve.c \
+    lib/lmcurve_tyd.c \
+    lib/lmmin.c
+
+LOCAL_MODULE := lmfit
+
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_STATIC_LIBRARY)
+