Re-enable Windows CI

[dtolnay]

clang-ast/.github/workflows/ci.yml

Lines 20 to 34 in 94dc08b

	windows:
	name: Windows
	runs-on: windows-latest
	steps:
	- uses: actions/checkout@v3
	- uses: dtolnay/rust-toolchain@stable
	- name: Add clang path to $PATH env
	run: echo "C:\msys64\mingw64\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
	- run: cargo test --release
	# Clang 13 does not understand Microsoft Visual Studio 2022's standard
	# library implementation. It's worked fine against older MSVC so
	# hopefully this job will start working again at some point.
	# "cannot mangle this dependent-length array yet"
	# "cannot mangle this template type parameter type yet"
	continue-on-error: true

This job used to work but had to get disabled in 2871541.