* config/alpha/alpha.h (TARGET_CPU_EV5, TARGET_CPU_EV6): Define.
(TARGET_OPTIONS): Add tune=.
(alpha_tune_string): Declare.
* config/alpha/alpha.c (override_options): Add cpu_table.
Use alpha_cpu_string first to set both alpha_cpu and target_flags
and then alpha_tune_string to set alpha_cpu only.
Replace tests for PROCESSOR_EV* with TARGET_CPU_EV* tests.
* config/alpha/elf.h (ASM_FILE_START): Likewise.
* config/alpha/osf.h (ASM_FILE_START): Likewise.
* config/alpha/openbsd.h (ASM_FILE_START): Likewise.