[patch, fortran] Introducing -fdump-optimized-tree

[Thomas Koenig]

Diego Novillo wrote:

> fdump-fortran-xxx?  Or perhaps have an umbrella fdump=...

fdump-fortran-original and fdump-fortran-optimized sounds good to me.

Should we keep fdump-parse-tree around as an alias for 4.6, then remove
it for 4.7?

	Thomas