Include Ruby exception message in VM interleaving error

[kateinoigakukun]

This would help debugging the nested VM operation error.

e.g.

RbFatalError: Ruby Fatal Error: Ruby APIs that may rewind the VM stack are prohibited under nested VM operation (rb_wasm_handle_jmp_unwind)
Nested VM operation means that the call stack has sandwitched JS frames like JS -> Ruby -> JS -> Ruby caused by something like `window.rubyVM.eval("JS.global[:rubyVM].eval('Fiber.yield')")`

Please check your call stack and make sure that you are **not** doing any of the following inside the nested Ruby frame:
  1. Switching fibers (e.g. Fiber#resume, Fiber.yield, and Fiber#transfer)
     Note that `evalAsync` JS API switches fibers internally
  2. Raising uncaught exceptions
     Please catch all exceptions inside the nested operation
  3. Calling Continuation APIs

/bundle/gems/js-2.5.0/lib/js.rb:180:in 'JS::Object#method_missing': undefined method '+' for an instance of JS::Object (NoMethodError)
/__root__/test/unit/test_object.rb:254:in 'block in JS::TestObject#test_new_with_block'
/bundle/gems/js-2.5.0/lib/js.rb:178:in 'JS::Object#call'
/bundle/gems/js-2.5.0/lib/js.rb:178:in 'JS::Object#method_missing'
/bundle/gems/js-2.5.0/lib/js.rb:144:in 'JS::Object#new'
/__root__/test/unit/test_object.rb:254:in 'JS::TestObject#test_new_with_block'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testcase.rb:871:in 'Test::Unit::TestCase#run_test'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testcase.rb:566:in 'block (2 levels) in Test::Unit::TestCase#run'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/fixture.rb:276:in 'block in Test::Unit::Fixture#create_fixtures_runner'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/fixture.rb:276:in 'block in Test::Unit::Fixture#create_fixtures_runner'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/fixture.rb:257:in 'Test::Unit::Fixture#run_fixture'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/fixture.rb:292:in 'Test::Unit::Fixture#run_setup'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testcase.rb:564:in 'block in Test::Unit::TestCase#run'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testcase.rb:563:in 'Kernel#catch'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testcase.rb:563:in 'Test::Unit::TestCase#run'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testsuite.rb:124:in 'Test::Unit::TestSuite#run_test'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testsuite.rb:53:in 'Test::Unit::TestSuite#run'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testsuite.rb:124:in 'Test::Unit::TestSuite#run_test'
/usr/local/lib/ruby/gems/3.4.0+0/gems/test-unit-3.6.1/lib/test/unit/testsuite.rb:53:in 'Test::Unit::TestSuite#run'