make frv use constraints.md
* config/frv/constraints.md: New file.
* config/frv/predicates.md: Include it.
* config/frv/frv.c (reg_class_from_letter): Delete.
(frv_option_override): Don't initialize it.
* config/frv/frv.h (REG_CLASS_FROM_LETTER): Delete.
(CONST_OK_FOR_I, CONST_OK_FOR_J, CONST_OK_FOR_K): Delete.
(CONST_OK_FOR_L, CONST_OK_FOR_M, CONST_OK_FOR_N): Delete.
(CONST_OK_FOR_O, CONST_OK_FOR_P, CONST_OK_FOR_LETTER_P): Delete.
(CONST_DOUBLE_OK_FOR_G, CONST_DOUBLE_OK_FOR_H): Delete.
(CONST_DOUBLE_OK_FOR_LETTER_P): Delete.
(EXTRA_CONSTRAINT_FOR_Q, EXTRA_CONSTRAINT_FOR_R): Delete.
(EXTRA_CONSTRAINT_FOR_S, EXTRA_CONSTRAINT_FOR_T): Delete.
(EXTRA_CONSTRAINT_FOR_U, EXTRA_CONSTRAINT): Delete.
(EXTRA_MEMORY_CONSTRAINT, CONSTRAINT_LEN): Delete.
(REG_CLASS_FROM_CONSTRAINT): Delete.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@170171
138bc75d-0d04-0410-961f-
82ee72b054a4