[PATCH] RISC-V: Bugfix for unrecognizable insn for XTheadVector

error: unrecognizable insn:

(insn 35 34 36 2 (set (subreg:RVVM1SF (reg/v:RVVM1x4SF 142 [ _r ]) 0)
        (unspec:RVVM1SF [
                (const_vector:RVVM1SF repeat [
                        (const_double:SF 0.0 [0x0.0p+0])
                    ])
                (reg:DI 0 zero)
                (const_int 1 [0x1])
                (reg:SI 66 vl)
                (reg:SI 67 vtype)
            ] UNSPEC_TH_VWLDST)) -1
     (nil))
during RTL pass: mode_sw

	PR target/116591

gcc/ChangeLog:

	* config/riscv/vector.md: Add restriction to call pred_th_whole_mov.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/xtheadvector/pr116591.c: New test.