Android doesn't have /proc/modules, and darling segfaults instead of
reporting errors elegantly. On BioniC, fclose(NULL) leads to SIGSEGV.

https://android.googlesource.com/platform/bionic/+/a8f9c8069ec45117393bc3abca3379cf62b1124e/libc/stdio/stdio.cpp#374

Android does not provide utilities like modprobe

glibc has bswap_32 => __bswap_32 => __builtin_bswap32
Android NDK has bswap_32 => __swap32 => __builtin_bswap32

Android NDK with x86_64 doesn't support -m32 with -ldl

Android does not have libpthread.so, and thus -pthread should be used
instead.

And skip components not applicable on Android

* fuse: Android's kernel do support fuse, but there's no libfuse.
Instead, those who need fuse, like the /system/bin/sdcard daemon,
talks to the kernel directly.
* udev: Android doesn't use udev. They use ueventd instead.

Host (ELF) executables like darling, mldr or wrapgen are not built with
-nostdinc, so there's no need to insert clang's include path manually.
On the other hand, cross-compiled darling and mldr may use a different
set of clang includes, which may cause conflicts. For example, Android
NDK uses customized headers in
$NDK/toolchains/llvm/prebuilt/linux-x86_64/lib64/clang/3.8.275480/include/

To support cross-compiled Darling, mldr and darling should be compiled
for target system wrapgen not. Split them for simpler build systems.

I can't merge now because of unstaged changes (sorry)

It is still not built by default, as it is broken

This was the same as f01f28650fefbf40c8ce42f2ae824458320e3644.
bfc5afc061a014311e74229ffc82281a9f5ed3c8 accidentally reverted it.

GNU patch is used by macOS instead

Add /bin/expr

This is for the `dsmemberutil` program, needed by the Homebrew installer

dyld -> startup
dyld-apple -> dyld

Fix running programs directly via `darling prog`