Add .gitignore files to exclude unit test build artifacts from git

With the addition of unit tests in commit
3ef3ba4d2eee36f64062a21ce030c3f4d8c4cac4, several additional build
artifacts are created:

  bin/depcomp
  bin/missing
  tests/Makefile
  tests/Makefile.in
  tests/glx/Makefile
  tests/glx/Makefile.in
  tests/glx/.deps/
  tests/glx/.gitignore

This patch adds all of these files to .gitignore.

Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
diff --git a/bin/.gitignore b/bin/.gitignore
new file mode 100644
index 0000000..3b3f168
--- /dev/null
+++ b/bin/.gitignore
@@ -0,0 +1,2 @@
+/depcomp
+/missing