(override_options): Set mips_abicalls.  Allow '^' as print operand
punctuation character.
(print_operand): Add support for '^'.
(mips_asm_file_start): Use ABICALLS_ASM_OP instead of ".abicalls".
(compute_frame_size): Handle TARGET_ABICALLS case.
(mips_expand_prologue): Likewise.

From-SVN: r5874