Update codegen_{cranelift,gcc} and opt-dist to use build.compiletest-allow-stage0

compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh

@@ -33,6 +33,7 @@ rustc = "$(pwd)/../dist/bin/rustc-clif"
 cargo = "$(rustup which cargo)"
 full-bootstrap = true
 local-rebuild = true
+compiletest-allow-stage0 = true
 
 [rust]
 download-rustc = false

compiler/rustc_codegen_cranelift/scripts/test_rustc_tests.sh

@@ -166,5 +166,5 @@ index 073116933bd..c3e4578204d 100644
 EOF
 
 echo "[TEST] rustc test suite"
-COMPILETEST_FORCE_STAGE0=1 ./x.py test --stage 0 --test-args=--no-capture tests/{codegen-units,run-make,ui,incremental}
+./x.py test --stage 0 --test-args=--no-capture tests/{codegen-units,run-make,ui,incremental}
 popd