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`

libc/intrin/kprintf.greg.c

@@ -438,7 +438,8 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, va_list va,
           i = 0;
           m = (1 << base) - 1;
           if (hash && x) sign = hash;
-          do z[i++ & 127] = abet[x & m];
+          do
+            z[i++ & 127] = abet[x & m];
           while ((x >>= base) || (pdot && i < prec));
           goto EmitNumber;
 
@@ -487,8 +488,8 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, va_list va,
           goto EmitChar;
 
         case 'm':
-          if (!(x = errno) && sign == ' ' &&
-              (!IsWindows() || !__imp_GetLastError())) {
+          if (!(x = errno) && sign == ' ' /*  && */
+              /* (!IsWindows() || !__imp_GetLastError()) */) {
             break;
           } else if (weaken(strerror_r) &&
                      !weaken(strerror_r)(x, z, sizeof(z))) {