libc++: patch tz impl to crash on windows instead of FTBFS

lib/libcxx/src/tz.cpp

@@ -45,7 +45,9 @@ _LIBCPP_WEAK string_view __libcpp_tzdb_directory() {
 #if defined(__linux__)
   return "/usr/share/zoneinfo/";
 #else
-#  error "unknown path to the IANA Time Zone Database"
+// Zig patch: change this compilation error into a runtime crash.
+//#  error "unknown path to the IANA Time Zone Database"
+  abort();
 #endif
 }