RFR(XXS): 8219441: test_logMessageTest missing static storage

[Robbin Ehn]

Hi, please review.

Issue: https://bugs.openjdk.java.net/browse/JDK-8219441

Clang finds this, compile tested clang + gcc.

Thanks, Robbin

diff -r 54a3ecb5a39b test/hotspot/gtest/logging/test_logMessageTest.cpp
--- a/test/hotspot/gtest/logging/test_logMessageTest.cpp	Wed Feb 20 09:41:00 
2019 +0100
+++ b/test/hotspot/gtest/logging/test_logMessageTest.cpp	Wed Feb 20 11:44:47 
2019 +0100
@@ -34,16 +34,18 @@
  class LogMessageTest : public LogTestFixture {
  protected:
    static Log(logging) _log;
    static const char* _level_filename[];
    LogMessageTest();
    ~LogMessageTest();
  };

+Log(logging) LogMessageTest::_log;
+
  const char* LogMessageTest::_level_filename[] = {
    NULL, // LogLevel::Off
  #define LOG_LEVEL(name, printname) "multiline-" #printname ".log",
    LOG_LEVEL_LIST
  #undef LOG_LEVEL
  };

  LogMessageTest::LogMessageTest() {