Fixing clippy issues, running ci-test-other with 2 worker threads

Author: udesou

.github/scripts/ci-test-other.sh

@@ -64,7 +64,7 @@ if [[ $CHOOSE_TESTS_JL_CONTENT =~ $REGEX_PATTERN ]]; then
             fi
 
             echo "-> Run"
-            ci_run_jl_test $test 1 $moving_feature
+            ci_run_jl_test $test 2 $moving_feature
         fi
     done
 else

mmtk/src/scanning.rs

@@ -132,7 +132,7 @@ impl Scanning<JuliaVM> for VMScanning {
                                 CONSERVATIVE_ROOTS.lock().unwrap().insert(obj);
                             }
 
-                            if let Some(jmpbuf) = (*eh).eh_ctx.get(0) {
+                            if let Some(jmpbuf) = (*eh).eh_ctx.first() {
                                 for buff in jmpbuf.__jmpbuf {
                                     if let Some(obj) =
                                         is_potential_mmtk_object(Address::from_usize(buff as usize))