[libc++][nfc] Add more nasty macros.

D101613 added some macros used by Microsofts SAL. D103425 uses `__pre`
and `__post`. They are also used by SAL and cause issues when used on
Windows. Add them to the blacklist making it easier to figure out what
the issue is.

Differential Revision: https://reviews.llvm.org/D103541

libcxx/test/support/nasty_macros.h

@@ -63,6 +63,8 @@
 #define __nz NASTY_MACRO
 #define __out NASTY_MACRO
 #define __part NASTY_MACRO
+#define __post NASTY_MACRO
+#define __pre NASTY_MACRO
 #endif
 
 #define __output NASTY_MACRO