Migrate CI to GitHub Actions

This commit migrates from Azure Pipelines to Github Actions for CI for
cranelift. The CI configuration was relatively straightforward, and the
intention here is not to change what's actually being done on CI, just
change where it's being done. The previous CI configuration had build
targets for producing releases, but these weren't actually applicable
for cranelift itself (mostly just copied from wasmtime), so they've been
folded into the main "test everything" matrix which now includes
`--release` mode items.

See cranestation/wasmtime#474 for some more context as well in terms of
benefits of Github Actions vs Azure Pipelines.

cranelift/ci/azure-build-release.yml

@@ -1,66 +0,0 @@
-steps:
-- checkout: self
-  submodules: true
-
-- template: azure-install-rust.yml
-
-- bash: echo "##vso[task.setvariable variable=RUSTC_VERSION;]`rustc --version`"
-  displayName: Set rustc version string for caching
-
-- bash: cargo build --release
-  displayName: Cargo build
-
-# Test what we're about to release in release mode itself.
-- bash: cargo test --release --all
-  displayName: Cargo test
-  env:
-    RUST_BACKTRACE: 1
-
-- bash: |
-    echo "##vso[task.setvariable variable=tagName;]`echo $BUILD_SOURCEBRANCH | sed -e 's|refs/tags/||'`"
-  displayName: Set tag name
-  condition: startsWith(variables['Build.SourceBranch'], 'refs/tags/')
-- bash: |
-    echo "##vso[task.setvariable variable=tagName;]dev"
-  displayName: Set tag name to "dev"
-  condition: not(startsWith(variables['Build.SourceBranch'], 'refs/tags/'))
-
-- bash: echo "##vso[task.setvariable variable=basename;]cranelift-$(tagName)-x86_64-windows"
-  displayName: Configure basename var
-  condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))
-- bash: echo "##vso[task.setvariable variable=basename;]cranelift-$(tagName)-x86_64-macos"
-  displayName: Configure basename var
-  condition: and(succeeded(), eq(variables['Agent.OS'], 'Darwin'))
-- bash: echo "##vso[task.setvariable variable=basename;]cranelift-$(tagName)-x86_64-linux"
-  displayName: Configure basename var
-  condition: and(succeeded(), eq( variables['Agent.OS'], 'Linux' ))
-
-- bash: |
-    set -e
-    mkdir -p $BUILD_BINARIESDIRECTORY/$BASENAME
-    if [ "$AGENT_OS" = "Windows_NT" ]; then
-      ext=.exe
-    fi
-    cp LICENSE README.md target/release/clif-util$ext $BUILD_BINARIESDIRECTORY/$BASENAME
-  displayName: Copy binaries
-
-- task: ArchiveFiles@2
-  inputs:
-    rootFolderOrFile: $(Build.BinariesDirectory)/$(basename)
-    archiveType: 'zip'
-    archiveFile: '$(Build.ArtifactStagingDirectory)/$(basename).zip'
-  displayName: Archive files (Win)
-  condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))
-- task: ArchiveFiles@2
-  inputs:
-    rootFolderOrFile: $(Build.BinariesDirectory)/$(basename)
-    archiveType: 'tar'
-    tarCompression: 'xz'
-    archiveFile: '$(Build.ArtifactStagingDirectory)/$(basename).tar.xz'
-  displayName: Archive files (Unix)
-  condition: and(succeeded(), ne(variables['Agent.OS'], 'Windows_NT'))
-- task: PublishPipelineArtifact@1
-  inputs:
-    path: $(Build.ArtifactStagingDirectory)/
-    artifactName: 'bundle-$(Agent.OS)'
-

cranelift/ci/azure-install-rust.yml

@@ -1,33 +0,0 @@
-steps:
-  # Rustup is currently installed on Windows and Linux, but not macOS.
-  # It is installed in /usr/local/cargo/bin/ or C:\Program Files\Rust\.cargo\bin\
-  # This steps ensures that rustup is installed, mainly for macOS, or if the
-  # azure image changes in the future.
-  - bash: |
-      set -ex
-      if [ -x "`command -v rustup`" ]; then
-        echo `command -v rustup` `rustup -V` already installed
-        rustup self update
-      else
-        if [ "$AGENT_OS" = "Windows_NT" ]; then
-          curl -sSf -o rustup-init.exe https://win.rustup.rs
-          ./rustup-init.exe -y --default-toolchain $TOOLCHAIN
-          echo "##vso[task.prependpath]$USERPROFILE/.cargo/bin"
-        else
-          curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain $TOOLCHAIN
-          echo "##vso[task.prependpath]$HOME/.cargo/bin"
-        fi
-      fi
-    displayName: Install rustup
-
-  - bash: |
-      set -ex
-      rustup update $TOOLCHAIN
-      rustup default $TOOLCHAIN
-    displayName: Install rust
-
-  - bash: |
-      set -ex
-      rustc -Vv
-      cargo -V
-    displayName: Query rust and cargo versions