`get_unchecked()` is never inlined on armv7-unknown-linux-gnueabihf in functions with `#[target_feature(enable = "neon")]`

[hkratz]

While working on armv7 neon support for simdutf8 I ran across inlining problems for functions with #[target_feature(enable = "neon")]. One of them is that get_unchecked() is never inlined in such functions.

More info:

• It also is not inlined with the armv7-linux-androideabi target
• It is inlined with the thumbv7neon-unknown-linux-gnueabihf target
• It is inlined if compiled with RUSTFLAGS="-Ctarget_feature=+neon"

#![feature(arm_target_feature)]

#[target_feature(enable = "neon")]
pub unsafe fn get_unchecked_range(x: &[u8]) -> &[u8] {
    // do more neon stuff
    unsafe { x.get_unchecked(3..)}
    // do more neon stuff
}

#[target_feature(enable = "neon")]
pub unsafe fn get_unchecked_one(x: &[u8]) -> &u8 {
    // do more neon stuff
    unsafe { x.get_unchecked(3)}
    // do more neon stuff
}

Godbolt

The root cause might be the same as for #102220.

[hkratz]

@rustbot label +A-target-feature +T-compiler +A-SIMD +A-codegen +O-arm