Update toolchain, get rid of the std-features hack

[Rahix]

The compiler-builtins-mangled-names thingie¹ is no longer needed, since compiler_builtins has been improved to avoid pulling the problematic functions:

• Fix division on AVRs rust-lang/compiler-builtins#462
• Add avr_skip for __udivti3 & __umodti3 rust-lang/compiler-builtins#466
• library/std: Bump compiler_builtins rust-lang/rust#97435

Suggested-by: @Patryk27
Link: Rahix/avr-hal-template#8

Footnotes

1. https://github.com/rust-lang/rust/issues/82242 ↩

[Rahix]

Hm, it seems it's not that simple... CI has found a problem with the new compiler-builtins:

error: linking with `avr-gcc` failed: exit status: 1
  |
  = note: "avr-gcc" "-mmcu=atmega328p" "-Wl,--as-needed" "/home/runner/work/avr-hal/avr-hal/target/avr-atmega328p/debug/deps/uno_infrared-5a3951b8d12057fc.infrared-6fde07c6bec00737.infrared.ef7898aa-cgu.0.rcgu.o.rcgu.o" "-Wl,--as-needed" "-L" "/home/runner/work/avr-hal/avr-hal/target/avr-atmega328p/debug/deps" "-L" "/home/runner/work/avr-hal/avr-hal/target/debug/deps" "-L" "/home/runner/.rustup/toolchains/nightly-2022-05-10-x86_64-unknown-linux-gnu/lib/rustlib/avr-atmega328p/lib" "-Wl,--start-group" "-Wl,--end-group" "-Wl,-Bstatic" "/home/runner/work/avr-hal/avr-hal/target/avr-atmega328p/debug/deps/libcompiler_builtins-2c6cd344c175bc84.rlib" "-Wl,-Bdynamic" "-lgcc" "-Wl,-znoexecstack" "-L" "/home/runner/.rustup/toolchains/nightly-2022-05-10-x86_64-unknown-linux-gnu/lib/rustlib/avr-atmega328p/lib" "-o" "/home/runner/work/avr-hal/avr-hal/target/avr-atmega328p/debug/deps/uno_infrared-5a3951b8d12057fc.elf" "-Wl,--gc-sections"
  = note: /home/runner/work/avr-hal/avr-hal/target/avr-atmega328p/debug/deps/libcompiler_builtins-2c6cd344c175bc84.rlib(compiler_builtins-2c6cd344c175bc84.compiler_builtins.2b21ae12-cgu.2.rcgu.o): In function `compiler_builtins::int::specialized_div_rem::u32_div_rem::habc400843d67f745':
          /home/runner/.rustup/toolchains/nightly-2022-05-10-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/num/uint_macros.rs:126: undefined reference to `core::panicking::panic::hc86d7a015ce76f79'
          collect2: error: ld returned 1 exit status

I thought the issue with compiler-builtins being compiled with overflow checks had been corrected?

[Rahix]

Ah, CI still used the old nightly release... Sorry for the noise.

[Patryk27]

Ah, CI still used the old nightly release... Sorry for the noise.

Almost thought I'm going crazy 😄