add Windows ARM64 support

Author: Harishmcw

.github/workflows/python-package.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        os: [ubuntu-latest, windows-latest, windows-11-arm, macos-latest]
         python-version:
           - "3.9"
           - "3.10"
@@ -19,7 +19,7 @@ jobs:
           - "pypy-3.8"
           - "pypy-3.9"
           - "pypy-3.10"
-        architecture: ["x86", "x64"]
+        architecture: ["x86", "x64", "arm64"]
         exclude:
           - os: macos-latest # No Numpy binary wheel
             python-version: "pypy-3.7"
@@ -35,6 +35,28 @@ jobs:
             python-version: "pypy-3.9"
           - os: windows-latest
             python-version: "pypy-3.10"
+          - os: windows-11-arm
+            python-version: "3.9"
+          - os: windows-11-arm
+            python-version: "3.10"
+          - os: windows-latest
+            architecture: "arm64"
+          - os: ubuntu-latest
+            architecture: "arm64"
+          - os: macos-latest
+            architecture: "arm64"
+          - os: windows-11-arm
+            architecture: "x86"
+          - os: windows-11-arm
+            architecture: "x64"
+          - os: windows-11-arm
+            python-version: "pypy-3.7"
+          - os: windows-11-arm
+            python-version: "pypy-3.8"
+          - os: windows-11-arm
+            python-version: "pypy-3.9"
+          - os: windows-11-arm
+            python-version: "pypy-3.10"
 
     steps:
       - uses: actions/checkout@v2

soundfile.py

@@ -169,11 +169,10 @@
     elif _sys.platform == 'win32':
         from platform import architecture as _architecture
         from platform import machine as _machine
-        # this check can not be completed correctly: for x64 binaries running on
-        # arm64 Windows report the same values as arm64 binaries. For now, neither
-        # numpy nor cffi are available for arm64, so we can safely assume we're
-        # in x86 land:
-        if _architecture()[0] == '64bit':
+        _win_machine = _machine().lower()
+        if _win_machine in ('arm64', 'aarch64'):
+            _packaged_libname = 'libsndfile_arm64.dll'
+        elif _architecture()[0] == '64bit':
             _packaged_libname = 'libsndfile_x64.dll'
         elif _architecture()[0] == '32bit':
             _packaged_libname = 'libsndfile_x86.dll'