Fix RVV intrinsic version detection. #131

Job	Run time
build-native-gcc	5m 5s
build-native-llvm	3m 47s
test-native-gcc	9m 25s
test-native-llvm	9m 13s
build-aarch64-gcc	6m 49s
build-aarch64-llvm	3m 2s
build-armhf-gcc	1m 25s
build-armhf-llvm	2m 50s
build-ppc64el-gcc	4m 8s
build-ppc64el-llvm	3m 7s
build-s390x-gcc	2m 21s
build-s390x-llvm	2m 29s
build-riscv64-llvm	3m 7s
test-aarch64-gcc (qemu_cpu: "max,sve=off")	17m 53s
test-aarch64-gcc (qemu_cpu: "max,sve=on,sve128=on")	21m 22s
test-aarch64-gcc (qemu_cpu: "max,sve=on,sve256=on")	25m 19s
test-aarch64-gcc (qemu_cpu: "max,sve=on,sve512=on")	31m 14s
test-aarch64-llvm (qemu_cpu: "max,sve=off")	15m 57s
test-aarch64-llvm (qemu_cpu: "max,sve=on,sve128=on")	20m 37s
test-aarch64-llvm (qemu_cpu: "max,sve=on,sve256=on")	25m 47s
test-aarch64-llvm (qemu_cpu: "max,sve=on,sve512=on")	29m 38s
test-armhf-gcc (qemu_cpu: "max")	14m 27s
test-armhf-llvm (qemu_cpu: "max")	13m 39s
test-ppc64el-gcc (qemu_cpu: "power10")	26m 37s
test-ppc64el-llvm (qemu_cpu: "power10")	24m 29s
test-s390x-gcc (qemu_cpu: "")	22m 53s
test-s390x-llvm (qemu_cpu: "")	18m 11s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=false")	12m 40s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=true,vlen=128,elen=64,vext_spec=v1.0")	29m 58s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=true,vlen=256,elen=64,vext_spec=v1.0")	39m 42s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=true,vlen=512,elen=64,vext_spec=v1.0")	45m 45s
	8h 12m 56s

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