layout: restructure into src/ tests/ android/ scripts/ tools/

- extension/src/{port,platform,codepage} -> src/; native_render -> src/host
  (+ dxt, shaders/); libgr2 -> src/gr2; extension/third_party -> third_party
- extension/tests -> tests/port, libgr2/tests -> tests/gr2
- android-native -> android (build.sh, push-client.sh moved in)
- script -> scripts; tools/40250 -> tools/server; oracle -> tools/granny-oracle;
  perf tools -> tools/perf
- all build trees under build/ (native, release, android, port-gate)
- xrender:: CMake aliases -> mt::; port-map ledger impl paths rewritten

No code changes. ctest 15/15, port_gate macos+android PASS, port_map check 0 errors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

third_party/cpython-2.7.18/Include/osdefs.h

@@ -0,0 +1,63 @@
+#ifndef Py_OSDEFS_H
+#define Py_OSDEFS_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Operating system dependencies */
+
+/* Mod by chrish: QNX has WATCOM, but isn't DOS */
+#if !defined(__QNX__)
+#if defined(MS_WINDOWS) || defined(__BORLANDC__) || defined(__WATCOMC__) || defined(__DJGPP__) || defined(PYOS_OS2)
+#if defined(PYOS_OS2) && defined(PYCC_GCC)
+#define MAXPATHLEN 260
+#define SEP '/'
+#define ALTSEP '\\'
+#else
+#define SEP '\\'
+#define ALTSEP '/'
+#define MAXPATHLEN 256
+#endif
+#define DELIM ';'
+#endif
+#endif
+
+#ifdef RISCOS
+#define SEP '.'
+#define MAXPATHLEN 256
+#define DELIM ','
+#endif
+
+
+/* Filename separator */
+#ifndef SEP
+#define SEP '/'
+#endif
+
+/* Max pathname length */
+#ifdef __hpux
+#include <sys/param.h>
+#include <limits.h>
+#ifndef PATH_MAX
+#define PATH_MAX MAXPATHLEN
+#endif
+#endif
+
+#ifndef MAXPATHLEN
+#if defined(PATH_MAX) && PATH_MAX > 1024
+#define MAXPATHLEN PATH_MAX
+#else
+#define MAXPATHLEN 1024
+#endif
+#endif
+
+/* Search path entry delimiter */
+#ifndef DELIM
+#define DELIM ':'
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_OSDEFS_H */