Kito's 5-part patch set to improve .insn support.

Kito's 5-part patch set to improve .insn support.

	From Kito Cheng <kito.cheng@sifive.com>
	gas/ChangeLog
	* doc/c-riscv.texi (Instruction Formats): Add r4 type.
	* testsuite/gas/riscv/insn.d: Add testcase for r4 type.
	* testsuite/gas/riscv/insn.s: Ditto.
	* doc/c-riscv.texi (Instruction Formats): Add b and j type.
	* testsuite/gas/riscv/insn.d: Add test case for b and j type.
	* testsuite/gas/riscv/insn.s: Ditto.
	* testsuite/gas/riscv/insn.s: Correct instruction type for load
	and store.
	* testsuite/gas/riscv/insn.d: Using regular expression to match
	address.
	* doc/c-riscv.texi (Instruction Formats): Fix encoding table for SB
	type and fix typo.
	opcode/ChangeLog
	* riscv-opc.c (riscv_insn_types): Add r4 type.
	* riscv-opc.c (riscv_insn_types): Add b and j type.
	* opcodes/riscv-opc.c (riscv_insn_types): Remove incorrect
	format for sb type and correct s type.