Eliminate some flakes

- Get ASAN working on Windows.

- Deleting directories and then recreating them with the same name in a
  short period of time appears to be a no-no on Windows.

- There's no reason to call FlushFileBuffers on close() for pipes, and
  it's harmful since it might block indefinitely for no good reason.

tool/viz/printpeb.c

@@ -80,7 +80,7 @@ const struct IdName kNtStartfFlagNames[] = {
     {0, 0},
 };
 
-void PrintStartupInfo(void) {
+noasan void PrintStartupInfo(void) {
   printf("\n\
 ╔──────────────────────────────────────────────────────────────────────────────╗\n\
 │ new technology § startup info                                                │\n\
@@ -155,7 +155,7 @@ void PrintStdioInfo(void) {
          ft2str(GetFileType(g_fds.p[2].handle)));
 }
 
-void PrintTeb(void) {
+noasan void PrintTeb(void) {
   GetCurrentProcessId();
   SetLastError(0x1234);
   printf("\n\