further improve panic_immediate_abort by removing rtprintpanic! messages

[klensy]

Reduces binary size using panic_immediate_abort by removing strings used by rtprintpanic!.

for main.rs

fn main() {
    println!("Hello, world!");
}

with Cargo.toml

[package]
name = "tst"
version = "0.1.0"
edition = "2024"

[dependencies]

[profile.release]
lto = true
codegen-units = 1
panic = "abort"

and build with RUSTFLAGS="-Zlocation-detail=none -Zfmt-debug=none" cargo +stage-1 b -r -Z build-std=std,panic_abort -Z build-std-features=optimize_for_size,panic_immediate_abort for x86_64-unknown-linux-gnu

This reduces size:

before	after	type
25256	21880	unstripped
18072	15288	stripped

[rustbot]

r? @Mark-Simulacrum

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[Mark-Simulacrum]

Seems OK; the cfg is unstable and is documented to not format output.

@bors r+

[bors]

📌 Commit 3a0554a has been approved by Mark-Simulacrum

It is now in the queue for this repository.