appveyor.yml: execute test_syntax separately

because NoMemoryError tends to be caused by
TestSyntax#assert_syntax_files.
https://ci.appveyor.com/project/ruby/ruby/build/1.0.8525
https://ci.appveyor.com/project/ruby/ruby/build/1.0.8795
https://ci.appveyor.com/project/ruby/ruby/builds/19334828/job/s1960qssxnk1lpoi

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64962 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

appveyor.yml

@@ -92,9 +92,9 @@ for:
     - set /a JOBS=%NUMBER_OF_PROCESSORS%
     - nmake -l "TESTOPTS=-v -q" btest
     - nmake -l "TESTOPTS=-v -q" test-basic
-    - nmake -l "TESTOPTS=-q -j%JOBS% --subprocess-timeout-scale=1.5 --exclude win32ole" test-all RUBY_FORCE_TEST_JIT=1
+    - nmake -l "TESTOPTS=-q -j%JOBS% --subprocess-timeout-scale=1.5 --exclude win32ole --exclude test_syntax" test-all RUBY_FORCE_TEST_JIT=1
     # separately execute tests that may crash worker without -j.
-    - nmake -l "TESTOPTS=-q --subprocess-timeout-scale=1.5" test-all TESTS="../test/win32ole"
+    - nmake -l "TESTOPTS=-q --subprocess-timeout-scale=1.5" test-all TESTS="../test/win32ole ../test/ruby/test_syntax.rb"
     - nmake -l test-spec
 -
   matrix: