[win] Add mingw-ldd.py

Part of https://github.com/harfbuzz/harfbuzz/issues/1728

mingw-ldd.py

+#!/usr/bin/env python
+
+# Copied from https://github.com/xantares/mingw-ldd/blob/master/mingw-ldd.py
+# Modified to point to right prefix location on Fedora.
+
+# WTFPL - Do What the Fuck You Want to Public License
+from __future__ import print_function
+import pefile
+import os
+import sys
+
+
+def get_dependency(filename):
+    deps = []
+    pe = pefile.PE(filename)
+    for imp in pe.DIRECTORY_ENTRY_IMPORT:
+        deps.append(imp.dll.decode())
+    return deps
+
+
+def dep_tree(root, prefix=None):
+    if not prefix:
+        arch = get_arch(root)
+        #print('Arch =', arch)
+        prefix = '/usr/'+arch+'-w64-mingw32/sys-root/mingw/bin'
+        #print('Using default prefix', prefix)
+    dep_dlls = dict()
+
+    def dep_tree_impl(root, prefix):
+        for dll in get_dependency(root):
+            if dll in dep_dlls:
+                continue
+            full_path = os.path.join(prefix, dll)
+            if os.path.exists(full_path):
+                dep_dlls[dll] = full_path
+                dep_tree_impl(full_path, prefix=prefix)
+            else:
+                dep_dlls[dll] = 'not found'
+
+    dep_tree_impl(root, prefix)
+    return (dep_dlls)
+
+
+def get_arch(filename):
+    type2arch= {pefile.OPTIONAL_HEADER_MAGIC_PE: 'i686',
+                pefile.OPTIONAL_HEADER_MAGIC_PE_PLUS: 'x86_64'}
+    pe = pefile.PE(filename)
+    try:
+        return type2arch[pe.PE_TYPE]
+    except KeyError:
+        sys.stderr.write('Error: unknown architecture')
+        sys.exit(1)
+
+if __name__ == '__main__':
+    filename = sys.argv[1]
+    for dll, full_path in dep_tree(filename).items():
+        print(' ' * 7, dll, '=>', full_path)
+