Improve signals and memory protection

- Document sigaction()
- Simplify New Technology fork() code
- Testing and many bug fixes for mprotect()
- Distribute Intel Xed ILD in the amalgamation
- Turn Xed enums into defines to avoid DWARF bloat
- Improve polyfilling of SA_SIGINFO on BSDs and fix bugs
- setpgid(getpid(), getpid()) on Windows will ignore CTRL-C
- Work around issues relating to NT mappings being executable
- Permit automatic executable stack override via `ape_stack_pf`

third_party/python/Python/xedmodule.c

@@ -46,9 +46,9 @@ too short, and lower numbers represent other errors.");
 static PyObject *
 xed_ild(PyObject *self, PyObject *args)
 {
+    int e;
     Py_ssize_t n;
     const char *p;
-    enum XedError e;
     struct XedDecodedInst xedd;
     if (!PyArg_ParseTuple(args, "y#:ild", &p, &n)) return 0;
     xed_decoded_inst_zero_set_mode(&xedd, XED_MACHINE_MODE_LONG_64);