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/Python/dynload_atheos.c

@@ -0,0 +1,47 @@
+
+/* Support for dynamic loading of extension modules */
+
+#include <atheos/image.h>
+#include <errno.h>
+
+#include "Python.h"
+#include "importdl.h"
+
+
+const struct filedescr _PyImport_DynLoadFiletab[] = {
+    {".so", "rb", C_EXTENSION},
+    {"module.so", "rb", C_EXTENSION},
+    {0, 0}
+};
+
+dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
+                                    const char *pathname, FILE *fp)
+{
+    void *p;
+    int lib;
+    char funcname[258];
+
+    if (Py_VerboseFlag)
+        printf("load_library %s\n", pathname);
+
+    lib = load_library(pathname, 0);
+    if (lib < 0) {
+        char buf[512];
+        if (Py_VerboseFlag)
+            perror(pathname);
+        PyOS_snprintf(buf, sizeof(buf), "Failed to load %.200s: %.200s",
+                      pathname, strerror(errno));
+        PyErr_SetString(PyExc_ImportError, buf);
+        return NULL;
+    }
+    PyOS_snprintf(funcname, sizeof(funcname), "init%.200s", shortname);
+    if (Py_VerboseFlag)
+        printf("get_symbol_address %s\n", funcname);
+    if (get_symbol_address(lib, funcname, -1, &p) < 0) {
+        p = NULL;
+        if (Py_VerboseFlag)
+            perror(funcname);
+    }
+
+    return (dl_funcptr) p;
+}