Make some systemic improvements

- add vdso dump utility
- tests now log stack usage
- rename g_ftrace to __ftrace
- make internal spinlocks go faster
- add conformant c11 atomics library
- function tracing now logs stack usage
- make function call tracing thread safe
- add -X unsecure (no ssl) mode to redbean
- munmap() has more consistent behavior now
- pacify fsync() calls on python unit tests
- make --strace flag work better in redbean
- start minimizing and documenting compiler flags

libc/sysv/strace.greg.c

@@ -16,6 +16,28 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/strace.internal.h"
+#include "libc/runtime/runtime.h"
 
-int __strace;
+/**
+ * System call logging enabled state.
+ *
+ * If Cosmopolitan was compiled with the `SYSDEBUG` macro (this is the
+ * default behavior, except in tiny and release modes) then `__strace`
+ * shall control whether or not system calls are logged to fd 2. If it's
+ * greater than zero, syscalls are logged. Otherwise, they're aren't.
+ *
+ * By convention, functions wishing to disable syscall tracing for a
+ * short time period should say:
+ *
+ *     void foo() {
+ *       --__strace;
+ *       bar();
+ *       ++__strace;
+ *     }
+ *
+ * This way you still have some flexibility to force syscall tracing, by
+ * setting `__strace` to a higher number like `2` or `200`. Even though
+ * under normal circumstances, `__strace` should only be either zero or
+ * one.
+ */
+_Atomic(int) __strace;