Rewrite Windows poll()

We can now await signals, files, pipes, and console simultaneously. This
change also gives a deeper review and testing to changes made yesterday.

Author: jart

examples/spawn_bench.c

@@ -117,6 +117,11 @@ int main(int argc, char *argv[]) {
   void *p;
   const char *prog;
 
+  // if you need the tiny64 program for windows:
+  //
+  //     make -j o//tool/hello/life-pe.ape
+  //     scp o//tool/hello/life-pe.ape windows:tiny64
+  //
   if (argc <= 1) {
     prog = "tiny64";
   } else {

libc/calls/internal.h

@@ -26,7 +26,6 @@ uint32_t sys_getuid_nt(void);
 int __ensurefds_unlocked(int);
 void __printfds(struct Fd *, size_t);
 int CountConsoleInputBytes(void);
-int CountConsoleInputBytesBlocking(uint32_t, sigset_t);
 int FlushConsoleInputBytes(void);
 int64_t GetConsoleInputHandle(void);
 int64_t GetConsoleOutputHandle(void);