PATCH: Remove redundant instructions after regcprop

[Paulo J. Matos]

Forgot to mention: this is to fix PR 54154.

Updated changelog:

2012-08-02   Paulo Matos <Paulo.Matos@csr.com>

     PR middle-end/54154
     * regcprop.c (copy_value): remove check for redundant moves.
     * regcprop.c (copy_value): add check for redundant moves,
     remove instructions if redundant.