Restart CI for New Technology and UBSAN hunting

Continuous Integration (via runit and runitd) is now re-enabled on win7
and win10. The `make test` command, which runs the tests on all systems
is now the fastest and most stable it's been since the project started.

UBSAN is now enabled in MODE=dbg in addition to ASAN. Many instances of
undefined behavior have been removed. Mostly things like passing a NULL
argument to memcpy(), which works fine with Cosmopolitan Libc, but that
doesn't prevents the compiler from being unhappy. There was an issue w/
GNU make where static analysis claims a sprintf() call can overflow. We
also now have nicer looking crash reports on Windows since uname should
now be supported and msys64 addr2line works reliably.

libc/log/backtrace2.c

@@ -79,7 +79,7 @@ static int PrintBacktraceUsingAddr2line(int fd, const struct StackFrame *bp) {
    * DWARF is a weak standard. Platforms that use LLVM or old GNU
    * usually can't be counted upon to print backtraces correctly.
    */
-  if (!IsLinux() /* && !IsWindows() */) {
+  if (!IsLinux() && !IsWindows()) {
     ShowHint("won't print addr2line backtrace because probably llvm");
     return -1;
   }