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

third_party/getopt/getopt.internal.h

@@ -11,7 +11,6 @@
 #define optreset __optreset
 #define getopt   __getopt
 
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 extern char *optarg;
@@ -20,5 +19,4 @@ extern int optind, opterr, optopt, optreset;
 int getopt(int, char *const[], const char *) paramsnonnull();
 
 COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* COSMOPOLITAN_GETOPT_H_ */

third_party/getopt/getsubopt.c

@@ -29,7 +29,6 @@
 │ SUCH DAMAGE.                                                                 │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/str/str.h"
-// clang-format off
 
 /*
  * The SVID interface to getsubopt provides no way of figuring out which

third_party/getopt/long.c

@@ -3,7 +3,6 @@
 #include "libc/str/str.h"
 #include "third_party/getopt/long1.h"
 #include "third_party/getopt/long2.h"
-// clang-format off
 
 /*	$OpenBSD: getopt_long.c,v 1.32 2020/05/27 22:25:09 schwarze Exp $	*/
 /*	$NetBSD: getopt_long.c,v 1.15 2002/01/31 22:43:40 tv Exp $	*/

third_party/getopt/long1.h

@@ -3,7 +3,6 @@
 #ifdef COSMOPOLITAN_GETOPT_H_
 #error "don't mix getopt_long() with cosmo's getopt()"
 #endif
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 extern char *optarg;
@@ -12,5 +11,4 @@ extern int optind, opterr, optopt, optreset;
 int getopt(int, char *const *, const char *);
 
 COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* _GETOPT_CORE_H */

third_party/getopt/long2.h

@@ -8,7 +8,6 @@
 #define required_argument 1
 #define optional_argument 2
 
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 struct option {
@@ -23,5 +22,4 @@ int getopt_long_only(int, char *const *, const char *, const struct option *,
                      int *);
 
 COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* _GETOPT_EXT_H */