re PR rtl-optimization/8812 ([avr] Registers allocated for two uses at once)

re PR rtl-optimization/8812 ([avr] Registers allocated for two uses at once)

PR target/8812
* reload1.c (choose_reload_regs): For equiv reg, add loop over all
hard regs for reload_reg_used_at_all and reg_class_contents checks.

From-SVN: r67751