Musl Patch
==========

riscv64gc-unknown-linux-musl gets promoted to tier 2 and `crt_static_default`
is updated to false in rust-lang/rust#122049,
which triggers rust-lang/rust#82521 (comment)
when building stage2 library artifacts
(riscv64gc-unknown-linux-gnu -> riscv64gc-unknown-linux-musl).

I patched it to re-enable `crt_static_default` for `riscv64gc-unknown-linux-musl`
to fix the build and align with the behavior on x86 Arch Linux, where `rust-musl`
defaults to statically link musl.

Wasm compiler_builtins bug
==========================

Wasm compiler_builtins rlib from built `rust-wasm` package includes objects for
host architecture(riscv64 in our case, and x86_64 for x86 Arch Linux).
This is not reproducible for toolchains installed via rustup so I have reported it
to Arch Linux:
https://gitlab.archlinux.org/archlinux/packaging/packages/rust/-/issues/3

Complications when building 1.82.0
==================================

rust-lang/rust#125016 landed in 1.82.0, which breaks
building rust 1.82.0 using our packaged rust 1.81.0.
Compiling the new compiler_builtins component requires a rustc compiler that
includes
rust-lang/rust@99e6a28
but unfortunately 1.81.0 does not, leading to the following ICE:
https://archriscv.felixc.at/.status/log.htm?url=logs/rust/rust-1:1.82.0-1.log

    internal compiler error: compiler/rustc_codegen_llvm/src/abi.rs:126:22: unsupported float: Reg { kind: Float, size: Size(2 bytes) }

This is mitigated upstream by bumping stage0 to 1.82:
rust-lang/rust#129268 (comment)

So we need to first build 1.82.0 rustc once without the f16/f128 handling part
in compiler_builtins, to get a compiler that is capable of handling f16/f128.
And then we can use this compiler to compile compiler_builtins with f16/f128 handling.
It's not easy to do so in one patch. The most easy way is to build and package
rust 1.82.0 twice. This PR covers the first part and disable-f16-f128.diff will
be removed in the second part.