remove cruft from x86_64 syscall.h

x86_64 syscall.h defined some musl internal syscall names and made
them public. These defines were already moved to src/internal/syscall.h
(except for SYS_fadvise which is added now) so the cruft in x86_64
syscall.h is not needed.

arch/x86_64/bits/syscall.h

@@ -322,17 +322,6 @@
 #define __NR_bpf				321
 
 
-#undef __NR_fstatat
-#undef __NR_pread
-#undef __NR_pwrite
-#undef __NR_getdents
-#define __NR_fstatat __NR_newfstatat
-#define __NR_pread __NR_pread64
-#define __NR_pwrite __NR_pwrite64
-#define __NR_getdents __NR_getdents64
-#define __NR_fadvise __NR_fadvise64
-
-
 
 /* Repeat with SYS_ prefix */
 
@@ -658,15 +647,3 @@
 #define SYS_memfd_create			319
 #define SYS_kexec_file_load			320
 #define SYS_bpf					321
-
-#undef SYS_fstatat
-#undef SYS_pread
-#undef SYS_pwrite
-#undef SYS_getdents
-#define SYS_fstatat SYS_newfstatat
-#define SYS_pread SYS_pread64
-#define SYS_pwrite SYS_pwrite64
-#define SYS_getdents SYS_getdents64
-#define SYS_fadvise SYS_fadvise64
-
-

src/internal/syscall.h

@@ -191,6 +191,9 @@ long __syscall_ret(unsigned long), __syscall(syscall_arg_t, ...),
 #ifdef SYS_fadvise64_64
 #undef SYS_fadvise
 #define SYS_fadvise SYS_fadvise64_64
+#elif defined(SYS_fadvise64)
+#undef SYS_fadvise
+#define SYS_fadvise SYS_fadvise64
 #endif
 
 #ifdef SYS_sendfile64