[rs] add cranelift compiler

rs/build_cranelift_debug.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+set -eu
+
+cd $(dirname $0)
+BUILDDIR=${BUILD_ROOT:-target}/$(basename $(pwd))-cranelift-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
+export CARGO_PROFILE_DEV_CODEGEN_BACKEND=cranelift
+export CARGO_TARGET_DIR=$BUILDDIR
+cargo +nightly build -Zcodegen-backend --release
+cp $BUILDDIR/debug/rosettaboy-rs ./rosettaboy-cranelift

utils/Dockerfile

@@ -94,6 +94,9 @@ USER dev
 ENV PATH="/home/dev/.cargo/bin:$PATH"
 RUN wget -qO - https://sh.rustup.rs | sh -s -- --default-toolchain ${RUST_VERSION} -y && \
     cargo search foo
+# Cranelift is only in nightly
+RUN rustup toolchain install nightly \
+    && rustup component add rustc-codegen-cranelift-preview --toolchain nightly
 
 
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