MJIT: Ignore existence of .bundle.dSYM on macOS

We could fix it, but removing files in the directory recursively is
tedious in C and --mjit-debug is not a concern for users. We have
TestMJITDebug for detecting linker problems that are ignored by -O. It's
not really for maintaining --mjit-debug itself.

test/ruby/test_mjit.rb

@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+require 'shellwords'
 require 'test/unit'
 require 'tmpdir'
 require_relative '../lib/jit_support'
@@ -710,10 +711,12 @@ class TestMJIT < Test::Unit::TestCase
       if RUBY_PLATFORM.match?(/mswin/)
         # "Permission Denied" error is preventing to remove so file on AppVeyor/RubyCI.
         omit 'Removing so file is randomly failing on AppVeyor/RubyCI mswin due to Permission Denied.'
-      else
-        # verify .c files are deleted on unload_units
-        assert_send([Dir, :empty?, dir], debug_info)
       end
+      if RUBY_PLATFORM.match?(/darwin/)
+        omit '.bundle.dSYM directory is left but removing it is not supported for now'
+      end
+      # verify .c files are deleted on unload_units
+      assert_send([Dir, :empty?, dir], debug_info)
     end
   end
 
@@ -998,10 +1001,13 @@ class TestMJIT < Test::Unit::TestCase
     if RUBY_PLATFORM.match?(/mswin/)
       omit 'Removing so file is randomly failing on AppVeyor/RubyCI mswin due to Permission Denied.'
     end
+    if RUBY_PLATFORM.match?(/darwin/)
+      omit '.bundle.dSYM directory is left but removing it is not supported for now'
+    end
     Dir.mktmpdir("jit_test_clean_so_") do |dir|
       code = "x = 0; 10.times {|i|x+=i}"
       eval_with_jit({"TMPDIR"=>dir}, code)
-      assert_send([Dir, :empty?, dir])
+      assert_send([Dir, :empty?, dir], "Directory #{dir} was not empty:\n#{Dir.glob("#{dir}/*").join("\n")}\n")
       eval_with_jit({"TMPDIR"=>dir}, code, save_temps: true)
       assert_not_send([Dir, :empty?, dir])
     end
@@ -1012,6 +1018,9 @@ class TestMJIT < Test::Unit::TestCase
       # TODO: check call stack and close handle of code which is not on stack, and remove objects on best-effort basis
       omit 'Removing so file being used does not work on Windows'
     end
+    if RUBY_PLATFORM.match?(/darwin/)
+      omit '.bundle.dSYM directory is left but removing it is not supported for now'
+    end
     Dir.mktmpdir("jit_test_clean_objects_on_exec_") do |dir|
       eval_with_jit({"TMPDIR"=>dir}, "#{<<~"begin;"}\n#{<<~"end;"}", min_calls: 1)
       begin;
@@ -1173,6 +1182,9 @@ class TestMJIT < Test::Unit::TestCase
       assert_equal("Successful MJIT finish\n" * 2, err.gsub(/^#{JIT_SUCCESS_PREFIX}:[^\n]+\n/, ''), debug_info)
 
       # ensure objects are deleted
+      if RUBY_PLATFORM.match?(/darwin/)
+        omit '.bundle.dSYM directory is left but removing it is not supported for now'
+      end
       assert_send([Dir, :empty?, dir], debug_info)
     end
   end if defined?(fork)