rustix: fixes for Android musl build

Android doesn't only have a bionic toolchain, but musl
toolchain for components built on the build workstation.

Author: gsingh408

src/backend/libc/c.rs

@@ -489,7 +489,8 @@ pub(super) use readwrite_pv64v2::{preadv64v2 as preadv2, pwritev64v2 as pwritev2
 #[cfg(feature = "fs")]
 #[cfg(all(
     linux_like,
-    not(any(target_os = "android", target_os = "emscripten", target_env = "gnu"))
+    linux_raw_dep,
+    not(any(target_os = "emscripten", target_env = "gnu"))
 ))]
 mod statx_flags {
     pub(crate) use linux_raw_sys::general::{
@@ -507,7 +508,8 @@ mod statx_flags {
 #[cfg(feature = "fs")]
 #[cfg(all(
     linux_like,
-    not(any(target_os = "android", target_os = "emscripten", target_env = "gnu"))
+    linux_raw_dep,
+    not(any(target_os = "emscripten", target_env = "gnu"))
 ))]
 pub(crate) use statx_flags::*;
 

src/backend/libc/fs/syscalls.rs

@@ -2053,10 +2053,7 @@ pub(crate) fn statx(
     // doesn't represent all the known flags.
     //
     // [it's deprecated]: https://patchwork.kernel.org/project/linux-fsdevel/patch/20200505095915.11275-7-mszeredi@redhat.com/
-    #[cfg(not(target_env = "musl"))]
     const STATX__RESERVED: u32 = c::STATX__RESERVED as u32;
-    #[cfg(target_env = "musl")]
-    const STATX__RESERVED: u32 = linux_raw_sys::general::STATX__RESERVED;
     if (mask.bits() & STATX__RESERVED) == STATX__RESERVED {
         return Err(io::Errno::INVAL);
     }