on loongarch host, LSX vec get wrong result

Host environment

• Operating system: openEuler 22.03
• OS/kernel version: 6.7.0-rc8+
• Architecture: loongarch
• QEMU flavor: qemu-loongarch64
• QEMU version: 8.2.50
• QEMU command line: qemu-loongarch64 test

Description of problem

on loongarch host, the lsx insns get wrong result.

Steps to reproduce

1. build linux-user on loongarch host with '--configure --target-list ='loongarch64-linux-user''
2. build test code 'gcc --static test.c -o test'
3. run './build/qemu-loongarch64 test'

Additional information

run 'qemu-loongarch64 test' the result is

0: 2f2f2f2f 1: 0 2: 2f2f2f2f 3: 0 4: ffffffff 5: 0 6: ffffffff 7: ffffffff

and the 6 or 7 may be ffffff or 0.

run 'test' on loongarch host or run qemu-loongarch64 on x86_64 host. the result is

0: 2f2f2f2f 1: 0 2: 2f2f2f2f 3: 0 4: 0 5: 0 6: 0 7: 0

for more infomation see log.txt