Add filename completion to d8's bash completion.

Review URL: https://chromiumcodereview.appspot.com/9346017

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10623 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/bash-completion.sh

@@ -48,7 +48,7 @@ _v8_flag() {
     cat src/d8.cc \
     | grep "strcmp(argv\[i\]" \
     | sed -ne 's/^[^"]*"--\([^"]*\)".*/--\1/p')
-  COMPREPLY=($(compgen -W "$targets" -- "$cur"))
+  COMPREPLY=($(compgen -W "$targets" -- "$cur") $(compgen -f -- "$cur"))
   return 0
 }