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/linenoise/linenoise.c

@@ -139,7 +139,7 @@
 #include "libc/errno.h"
 #include "libc/fmt/conv.h"
 #include "libc/intrin/asan.internal.h"
-#include "libc/intrin/bits.h"
+#include "libc/serialize.h"
 #include "libc/intrin/bsr.h"
 #include "libc/intrin/nomultics.internal.h"
 #include "libc/intrin/strace.internal.h"

third_party/linenoise/linenoise.h

@@ -2,7 +2,6 @@
 #define COSMOPOLITAN_THIRD_PARTY_LINENOISE_LINENOISE_H_
 #include "libc/calls/struct/winsize.h"
 #include "libc/stdio/stdio.h"
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 struct linenoiseState;
@@ -51,5 +50,4 @@ void linenoiseRefreshLine(struct linenoiseState *);
 char *linenoiseRaw(const char *, int, int) __wur;
 
 COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* COSMOPOLITAN_THIRD_PARTY_LINENOISE_LINENOISE_H_ */