Add new platform aarch64-mingw-ucrt aka Windows on ARM

It fits to the latest RubyInstaller release:
  https://rubyinstaller.org/2025/01/19/rubyinstaller-3.4.1-2-released.html

The llvm binaries are taken from https://github.com/mstorsjo/llvm-mingw which looks pretty well maintained.
There's also a "Known issues" section, which lists some helpful instructions for porting.

Fixes #148

Author: larskanis

.github/workflows/ci.yml

@@ -48,6 +48,7 @@ jobs:
           - platform: aarch64-linux-gnu
             alias:    aarch64-linux
           - platform: aarch64-linux-musl
+          - platform: aarch64-mingw-ucrt
           - platform: arm-linux-gnu
             alias:    arm-linux
           - platform: arm-linux-musl

.github/workflows/publish-images.yml

@@ -15,6 +15,7 @@ jobs:
         platform:
           - aarch64-linux-gnu
           - aarch64-linux-musl
+          - aarch64-mingw-ucrt
           - arm-linux-gnu
           - arm-linux-musl
           - arm64-darwin

.github/workflows/release-images.yml

@@ -22,6 +22,7 @@ jobs:
         platform:
           - aarch64-linux-gnu
           - aarch64-linux-musl
+          - aarch64-mingw-ucrt
           - arm-linux-gnu
           - arm-linux-musl
           - arm64-darwin

Dockerfile.mri.erb

@@ -24,6 +24,13 @@ COPY --from=larskanis/mingw64-ucrt:20.04 \
     /debs/
 RUN dpkg -i /debs/*.deb
 
+<% elsif platform =~ /aarch64-mingw-ucrt/ %>
+RUN wget https://github.com/mstorsjo/llvm-mingw/releases/download/20250114/llvm-mingw-20250114-ucrt-ubuntu-20.04-<%= RUBY_PLATFORM[/^\w+/] %>.tar.xz && \
+    tar xf llvm-mingw*.tar.xz && \
+    export MINGW_PATH=`ls -d llvm-mingw-*/` && \
+    echo "export PATH=`pwd`/$MINGW_PATH/bin:\$PATH" >> /etc/rubybashrc && \
+    rm -r $MINGW_PATH/bin/i686-w64* $MINGW_PATH/bin/armv7-w64* $MINGW_PATH/bin/x86_64-w64* $MINGW_PATH/i686-w64* $MINGW_PATH/armv7-w64* $MINGW_PATH/x86_64-w64*
+
 <% elsif platform =~ /linux-musl/ %>
 COPY build/mk_musl_cross.sh /tmp
 RUN /tmp/mk_musl_cross.sh <%= target %>
@@ -117,6 +124,10 @@ xrubies_build_plan = if platform =~ /x64-mingw-ucrt/
     # Rubyinstaller-3.1+ is platform x64-mingw-ucrt
     ["3.4.1:3.3.5:3.2.6:3.1.6", "3.1.6"],
   ]
+elsif platform =~ /aarch64-mingw-ucrt/
+  [
+    ["3.4.1", "3.1.6"],
+  ]
 elsif platform =~ /x64-mingw32/
   [
     # Rubyinstaller prior to 3.1 is platform x64-mingw32
@@ -130,7 +141,7 @@ else
   ]
 end
 
-strip = '-s' if platform !~ /darwin/
+strip = '-s' if platform !~ /darwin|aarch64-mingw/
 
 xrubies_build_plan.each do |xrubies, bootstrap_ruby_version| %>
 RUN bash -c " \
@@ -186,7 +197,7 @@ RUN find /usr/local/rake-compiler/ruby/*/*/lib/ruby -name rbconfig.rb | while re
 ##
 USER root
 
-<% if platform =~ /mingw/ %>
+<% if platform =~ /(x64|x86)-mingw/ %>
 # Install wrappers for strip commands as a workaround for "Protocol error" in boot2docker.
 COPY build/strip_wrapper_vbox /root/
 RUN mv /usr/bin/<%= target %>-strip /usr/bin/<%= target %>-strip.bin && \

README.md

@@ -16,6 +16,7 @@ The following platforms are supported for cross-compilation by rake-compiler-doc
 
 - `aarch64-linux` and `aarch64-linux-gnu`
 - `aarch64-linux-musl`
+- `aarch64-mingw-ucrt`
 - `arm-linux` and `arm-linux-gnu`
 - `arm-linux-musl`
 - `arm64-darwin`
@@ -193,6 +194,7 @@ This can be done like this:
 PLATFORMS = %w[
   aarch64-linux-gnu
   aarch64-linux-musl
+  aarch64-mingw-ucrt
   arm-linux-gnu
   arm-linux-musl
   arm64-darwin

Rakefile

@@ -12,6 +12,7 @@ platforms = [
   # tuple is [platform, target]
   ["aarch64-linux-gnu", "aarch64-linux-gnu"],
   ["aarch64-linux-musl", "aarch64-linux-musl"],
+  ["aarch64-mingw-ucrt", "aarch64-w64-mingw32"],
   ["arm-linux-gnu", "arm-linux-gnueabihf"],
   ["arm-linux-musl", "arm-linux-musleabihf"],
   ["arm64-darwin", "aarch64-apple-darwin"],

test/rcd_test/Rakefile

@@ -22,6 +22,7 @@ else
       aarch64-linux
       aarch64-linux-gnu
       aarch64-linux-musl
+      aarch64-mingw-ucrt
       arm-linux
       arm-linux-gnu
       arm-linux-musl