Reduce header complexity

- Remove most __ASSEMBLER__ __LINKER__ ifdefs
- Rename libc/intrin/bits.h to libc/serialize.h
- Block pthread cancelation in fchmodat() polyfill
- Remove `clang-format off` statements in third_party

net/https/certhasip.c

@@ -16,7 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/intrin/bits.h"
+#include "libc/serialize.h"
 #include "net/https/https.h"
 
 bool CertHasIp(const mbedtls_x509_crt *cert, uint32_t ip) {

net/https/https.h

@@ -7,7 +7,6 @@
 #include "third_party/mbedtls/pk.h"
 #include "third_party/mbedtls/ssl_ciphersuites.h"
 #include "third_party/mbedtls/x509_crt.h"
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 struct Cert {
@@ -40,5 +39,4 @@ struct Cert FinishCertificate(struct Cert *, mbedtls_x509write_cert *,
                               mbedtls_pk_context *);
 
 COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* COSMOPOLITAN_NET_HTTPS_HTTPS_H_ */