(TARGET_SWITCHES): Add float-vax and float-ieee.
({FUNCTION,LIBCALL}_VALUE, FUNCTION_VALUE_REGNO_P): R1 and R33 are also return
registers.
(ASM_OUTPUT_DOUBLE): Support both floating-point formats.
(PRINT_OPERAND_FUNCT_VALID_P): Add ',' and '-'.

From-SVN: r13184