i386.h (TARGET_CPU_CPP_BUILTINS): Change checking of ix86_arch and ix86_tune into a switch statement.
* config/i386/i386.h (TARGET_CPU_CPP_BUILTINS): Change checking
of ix86_arch and ix86_tune into a switch statement.
(enum processor_type): Default PROCESSOR_I386 to 0.
* config/i386/i386.c (ix86_decompose_address): Use TARGET_K6 instead
of "ix86_tune == PROCESSOR_K6".
(ia32_multipass_dfa_lookahead): Change checking of ix86_tune into
a switch statement.