RVV: add cmake toolchain for use Spike #63

	name: Ubuntu rvv VLEN=1024 (clang 17)

	# Fails due to the inability to install packages
	#on:
	# push:
	# branches:
	# - master
	# pull_request:
	# branches:
	# - master

	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- name: Install packages
	run: \|
	sudo sed 's/jammy/devel/g' -i /etc/apt/sources.list
	sudo apt-get update -q -y
	sudo apt-get install -y cmake make g++-riscv64-linux-gnu qemu-user-static clang-17
	- name: Build
	run: \|
	CXX=clang++-17 CXXFLAGS="--target=riscv64-linux-gnu -march=rv64gcv" cmake -DCMAKE_CROSSCOMPILING_EMULATOR=qemu-riscv64-static -DCMAKE_SYSTEM_PROCESSOR=riscv64 -DCMAKE_BUILD_TYPE=Release -B build
	cmake --build build/ -j$(nproc)
	- name: Test VLEN=1024
	run: \|
	export QEMU_LD_PREFIX="/usr/riscv64-linux-gnu"
	export QEMU_CPU="rv64,v=on,vlen=1024,rvv_ta_all_1s=on,rvv_ma_all_1s=on"
	ctest --output-on-failure --test-dir build -j $(nproc)

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