Make improvements

- You can now run `make -j8 toolchain` on Windows
- You can now run `make -j` on MacOS ARM64 and BSD OSes
- You can now use our Emacs dev environment on MacOS/Windows
- Fix bug where the x16 register was being corrupted by --ftrace
- The programs under build/bootstrap/ are updated as fat binaries
- The Makefile now explains how to download cosmocc-0.0.12 toolchain
- The build scripts under bin/ now support "cosmo" branded toolchains
- stat() now goes faster on Windows (shaves 100ms off `make` latency)
- Code cleanup and added review on the Windows signal checking code
- posix_spawnattr_setrlimit() now works around MacOS ARM64 bugs
- Landlock Make now favors posix_spawn() on non-Linux/OpenBSD
- posix_spawn() now has better --strace logging on Windows
- fstatat() can now avoid EACCES in more cases on Windows
- fchmod() can now change the readonly bit on Windows

libc/intrin/waitformultipleobjects.c

@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/intrin/strace.internal.h"
+#include "libc/nt/runtime.h"
 #include "libc/nt/synchronization.h"
 #include "libc/nt/thunk/msabi.h"
 
@@ -26,14 +27,15 @@ __msabi extern typeof(WaitForMultipleObjects)
 
 /**
  * Waits for handles to change status.
- * @note this wrapper takes care of ABI, STRACE(), and __winerr()
+ *
+ * @return -1u on error w/ GetLastError()
+ * @raise kNtErrorInvalidParameter if `bWaitAll` and `lpHandles` has dupes
  */
 uint32_t WaitForMultipleObjects(uint32_t nCount, const int64_t *lpHandles,
                                 bool32 bWaitAll, uint32_t dwMilliseconds) {
   uint32_t x;
   x = __imp_WaitForMultipleObjects(nCount, lpHandles, bWaitAll, dwMilliseconds);
-  if (x == -1u) __winerr();
-  POLLTRACE("WaitForMultipleObjects(%ld, %p, %hhhd, %'d) → %d% m", nCount,
-            lpHandles, bWaitAll, dwMilliseconds, x);
+  POLLTRACE("WaitForMultipleObjects(%ld, %p, %hhhd, %'d) → %d %d", nCount,
+            lpHandles, bWaitAll, dwMilliseconds, x, GetLastError());
   return x;
 }