.gitlab-ci.d/windows.yml: Enable native Windows symlink

The following error message was seen during the configure:

  "ln: failed to create symbolic link
  'x86_64-softmmu/qemu-system-x86_64.exe': No such file or directory"

By default the MSYS environment variable is not defined, so the runtime
behavior of winsymlinks is: if <target> does not exist, 'ln -s' fails.
At the configure phase, the qemu-system-x86_64.exe has not been built
so creation of the symbolic link fails hence the error message.

Set winsymlinks to 'native' whose behavior is most similar to the
behavior of 'ln -s' on *nix, that is:

  a) if native symlinks are enabled, and whether <target> exists
     or not, creates <destination> as a native Windows symlink;
  b) else if native symlinks are not enabled, and whether <target>
     exists or not, 'ln -s' creates as a Windows shortcut file.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220725123000.807608-1-bmeng.cn@gmail.com>
Message-Id: <20220725140520.515340-6-alex.bennee@linaro.org>

.gitlab-ci.d/windows.yml

@@ -57,6 +57,7 @@ msys2-64bit:
       mingw-w64-x86_64-zstd "
   - $env:CHERE_INVOKING = 'yes'  # Preserve the current working directory
   - $env:MSYSTEM = 'MINGW64'     # Start a 64 bit Mingw environment
+  - $env:MSYS = 'winsymlinks:native' # Enable native Windows symlink
   - .\msys64\usr\bin\bash -lc './configure --target-list=x86_64-softmmu
       --enable-capstone --without-default-devices'
   - .\msys64\usr\bin\bash -lc "sed -i '/^ROMS=/d' build/config-host.mak"
@@ -89,6 +90,7 @@ msys2-32bit:
       mingw-w64-i686-usbredir "
   - $env:CHERE_INVOKING = 'yes'  # Preserve the current working directory
   - $env:MSYSTEM = 'MINGW32'     # Start a 32-bit MinG environment
+  - $env:MSYS = 'winsymlinks:native' # Enable native Windows symlink
   - mkdir output
   - cd output
   - ..\msys64\usr\bin\bash -lc "../configure --target-list=ppc64-softmmu"