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.

libc/rand/rand.mk

@@ -24,14 +24,14 @@ LIBC_RAND_A_CHECKS =				\
 	$(LIBC_RAND_A_HDRS:%=o/$(MODE)/%.ok)
 
 LIBC_RAND_A_DIRECTDEPS =			\
-	LIBC_STUBS				\
-	LIBC_INTRIN				\
-	LIBC_TINYMATH				\
+	LIBC_CALLS				\
 	LIBC_NEXGEN32E				\
 	LIBC_NT_KERNEL32			\
 	LIBC_STR				\
+	LIBC_STUBS				\
+	LIBC_SYSV				\
 	LIBC_SYSV_CALLS				\
-	LIBC_SYSV
+	LIBC_TINYMATH
 
 LIBC_RAND_A_DEPS :=				\
 	$(call uniq,$(foreach x,$(LIBC_RAND_A_DIRECTDEPS),$($(x))))

libc/rand/rand64.c

@@ -33,7 +33,7 @@ hidden extern uint64_t g_rando64;
  *
  * @see rngset()
  */
-nodebuginfo uint64_t(rand64)(void) {
+nodebuginfo uint64_t rand64(void) {
   uint64_t res;
   if (X86_HAVE(RDRND)) {
     res = rdrand();

libc/rand/winrandish.c

@@ -16,11 +16,11 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
 #include "libc/nexgen32e/rdtsc.h"
 #include "libc/nt/dll.h"
 #include "libc/nt/events.h"
 #include "libc/nt/struct/point.h"
-#include "libc/nt/struct/teb.h"
 #include "libc/rand/rand.h"
 
 /**
@@ -29,7 +29,7 @@
 textwindows int64_t winrandish(void) {
   int64_t res;
   struct NtPoint point;
-  res = ((int64_t)NtGetPid() << 17) ^ NtGetTid() ^ rdtsc();
+  res = ((int64_t)getpid() << 17) ^ gettid() ^ rdtsc();
   /*
    * This function is intended for older CPUs built before 2012, so
    * let's avoid having our CUI apps yoink USER32.DLL until we're