Fixed the legacy build system

git-svn-id: https://svn.pjsip.org/repos/pjproject/branches/split-3rd-party@1202 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/third_party/build/os-darwinos.mak b/third_party/build/os-darwinos.mak
new file mode 100644
index 0000000..2e7dfe0
--- /dev/null
+++ b/third_party/build/os-darwinos.mak
@@ -0,0 +1,7 @@
+DIRS = resample
+DIRS += gsm
+DIRS += ilbc
+DIRS += speex
+DIRS += portaudio
+
+