Add Relocation Packer support

This only applies to shared libraries on the device, and like stripping,
we'll let make do the actual packing if we're embedded in Make.

Change-Id: I1585d74ecfc41e18dcbb5ffb70005adf007cc941
diff --git a/Android.bp b/Android.bp
index aee9123..0202ea7 100644
--- a/Android.bp
+++ b/Android.bp
@@ -126,6 +126,7 @@
         "cc/check.go",
         "cc/gen.go",
         "cc/makevars.go",
+        "cc/relocation_packer.go",
         "cc/sanitize.go",
         "cc/stl.go",
         "cc/strip.go",