RISC-V: Part-2: Save/Restore vector registers which need to be preversed

RISC-V: Part-2: Save/Restore vector registers which need to be preversed

Because functions which follow vector calling convention variant has
callee-saved vector reigsters but functions which follow standard calling
convention don't have. We need to distinguish which function callee is so that
we can tell GCC exactly which vector registers callee will clobber. So I encode
the callee's calling convention information into the calls rtx pattern like
AArch64. The old operand 2 and 3 of call pattern which copy from MIPS target are
useless and removed according to my analysis.

gcc/ChangeLog:

	* config/riscv/riscv-sr.cc (riscv_remove_unneeded_save_restore_calls): Pass riscv_cc.
	* config/riscv/riscv.cc (struct riscv_frame_info): Add new fileds.
	(riscv_frame_info::reset): Reset new fileds.
	(riscv_call_tls_get_addr): Pass riscv_cc.
	(riscv_function_arg): Return riscv_cc for call patterm.
	(get_riscv_cc): New function return riscv_cc from rtl call_insn.
	(riscv_insn_callee_abi): Implement TARGET_INSN_CALLEE_ABI.
	(riscv_save_reg_p): Add vector callee-saved check.
	(riscv_stack_align): Add vector save area comment.
	(riscv_compute_frame_info): Ditto.
	(riscv_restore_reg): Update for type change.
	(riscv_for_each_saved_v_reg): New function save vector registers.
	(riscv_first_stack_step): Handle funciton with vector callee-saved registers.
	(riscv_expand_prologue): Ditto.
	(riscv_expand_epilogue): Ditto.
	(riscv_output_mi_thunk): Pass riscv_cc.
	(TARGET_INSN_CALLEE_ABI): Implement TARGET_INSN_CALLEE_ABI.
	* config/riscv/riscv.h (get_riscv_cc): Export get_riscv_cc function.
	* config/riscv/riscv.md: Add CALLEE_CC operand for call pattern.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/base/abi-callee-saved-1-fixed-1.c: New test.
	* gcc.target/riscv/rvv/base/abi-callee-saved-1-fixed-2.c: New test.
	* gcc.target/riscv/rvv/base/abi-callee-saved-1-save-restore.c: New test.
	* gcc.target/riscv/rvv/base/abi-callee-saved-1-zcmp.c: New test.
	* gcc.target/riscv/rvv/base/abi-callee-saved-1.c: New test.
	* gcc.target/riscv/rvv/base/abi-callee-saved-2-save-restore.c: New test.
	* gcc.target/riscv/rvv/base/abi-callee-saved-2-zcmp.c: New test.
	* gcc.target/riscv/rvv/base/abi-callee-saved-2.c: New test.