gitignore: test-driver.

build-aux/.gitignore

@@ -7,21 +7,22 @@
 /config.rpath~
 /config.sub
 /depcomp
+/do-release-commit-and-tag
 /gendocs.sh
 /git-version-gen
 /gitlog-to-changelog
+/gnu-web-doc-update
+/gnupload
 /install-sh
 /javacomp.sh.in
 /javaexec.sh.in
 /link-warning.h
 /mdate-sh
 /missing
+/test-driver
 /texinfo.tex
 /update-copyright
 /useless-if-before-free
 /vc-list-files
 /warn-on-use.h
 /ylwrap
-/do-release-commit-and-tag
-/gnu-web-doc-update
-/gnupload