test_rubyoptions.rb: don't test --jit if not supported

test/lib/jit_support.rb: carved out JITSupport
test/ruby/test_jit.rb: ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62533 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/lib/jit_support.rb

@@ -0,0 +1,33 @@
+module JITSupport
+  JIT_TIMEOUT = 600 # 10min for each...
+  JIT_SUCCESS_PREFIX = 'JIT success \(\d+\.\dms\)'
+  SUPPORTED_COMPILERS = [
+    'gcc',
+    'clang',
+  ]
+
+  module_function
+  def eval_with_jit(script, verbose: 0, min_calls: 5, timeout: JIT_TIMEOUT)
+    EnvUtil.invoke_ruby(
+      ['--disable-gems', '--jit-wait', "--jit-verbose=#{verbose}", "--jit-min-calls=#{min_calls}", '-e', script],
+      '', true, true, timeout: timeout,
+    )
+  end
+
+  def supported?
+    # Experimental. If you want to ensure JIT is working with this test, please set this for now.
+    if ENV.key?('RUBY_FORCE_TEST_JIT')
+      return true
+    end
+
+    # Very pessimistic check. With this check, we can't ensure JIT is working.
+    begin
+      _, err = JITSupport.eval_with_jit('proc {}.call', verbose: 1, min_calls: 1, timeout: 10)
+    rescue Timeout::Error
+      $stderr.puts "TestJIT: #jit_supported? check timed out"
+      false
+    else
+      err.match?(JIT_SUCCESS_PREFIX)
+    end
+  end
+end