glfw: Use Dockerfile for ease to generate the embedding files for Windows

As MinGW version is specified, the result should be more deterministic.

Fixes #1201

internal/glfw/Dockerfile

@@ -0,0 +1,9 @@
+FROM debian:testing
+
+RUN apt-get update && apt-get install -y \
+        ca-certificates \
+        golang \
+        gcc-mingw-w64=10.1.0-3+23 \
+        && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /work

internal/glfw/gen.sh

@@ -0,0 +1 @@
+docker run --rm --volume $(pwd)/../..:/work $(docker build -q .) /bin/bash -c "cd ./internal/glfw; go run gen.go"

internal/glfw/generate.go

@@ -12,6 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:generate go run gen.go
+//go:generate sh ./gen.sh
 
 package glfw