Port a lot more code to AARCH64

- Introduce epoll_pwait()
- Rewrite -ftrapv and ffs() libraries in C code
- Use more FreeBSD code in math function library
- Get significantly more tests passing on qemu-aarch64
- Fix many Musl long double functions that were broken on AARCH64

libc/runtime/getpagesize.c

@@ -1,7 +1,7 @@
-/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
-│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
 ╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
 │                                                                              │
 │ Permission to use, copy, modify, and/or distribute this software for         │
 │ any purpose with or without fee is hereby granted, provided that the         │
@@ -16,14 +16,12 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/macros.internal.h"
+#include "libc/runtime/runtime.h"
 
-//	Returns granularity of memory manager.
-//
-//	@see	sysconf(_SC_PAGE_SIZE) which is portable
-getpagesize:
-	.leafprologue
-	.profilable
-	mov	$FRAMESIZE,%eax
-	.leafepilogue
-	.endfn	getpagesize,globl
+/**
+ * Returns granularity of memory manager.
+ * @see sysconf(_SC_PAGE_SIZE) which is portable
+ */
+int getpagesize(void) {
+  return FRAMESIZE;
+}

libc/runtime/internal.h

@@ -48,6 +48,7 @@ noasan void *_Mmap(void *addr, size_t size, int prot, int flags, int fd,
                    int64_t off) _Hide;
 noasan int _Munmap(char *, size_t) _Hide;
 void InitializeFileDescriptors(void);
+void __on_arithmetic_overflow(void);
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */