RISC-V: move struct vector_type_info from *.h to *.cc and change "user_name" into...

RISC-V: move struct vector_type_info from *.h to *.cc and change "user_name" into "name".

gcc/ChangeLog:

	* config/riscv/riscv-vector-builtins.cc (struct vector_type_info): Move
	from config/riscv/riscv-vector-builtins.h.
	(DEF_RVV_TYPE): Change USER_NAME to NAME.
	(register_vector_type): Change user_name to name.
	* config/riscv/riscv-vector-builtins.def (DEF_RVV_TYPE): Change
	USER_NAME to NAME.
	* config/riscv/riscv-vector-builtins.h (struct vector_type_info): Move
	to riscv-vector-builtins.cc.
	(DEF_RVV_TYPE): Change USER_NAME to NAME.

Reviewed-by: Kito Cheng <kito.cheng@sifive.com>