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/intrin/intrin.mk

@@ -25,7 +25,9 @@ LIBC_INTRIN_A_CHECKS =					\
 
 LIBC_INTRIN_A_DIRECTDEPS =				\
 	LIBC_STUBS					\
-	LIBC_NEXGEN32E
+	LIBC_SYSV					\
+	LIBC_NEXGEN32E					\
+	LIBC_NT_KERNEL32
 
 LIBC_INTRIN_A_DEPS :=					\
 	$(call uniq,$(foreach x,$(LIBC_INTRIN_A_DIRECTDEPS),$($(x))))