8009729: Refix hotspot jni_<cpu>.h JNIEXPORT and JNIIMPORT definitions to match jdk version

Summary: Update JNIEXPORT and JNIIMPORT to work with other compilers that don't necessarily have the __attribute__ type qualifier
Reviewed-by: dholmes, dcubed, coleenp

src/cpu/sparc/vm/jni_sparc.h

@@ -23,7 +23,12 @@
  * questions.
  */
 
-#if defined(__GNUC__) && (__GNUC__ >= 4)
+// Note: please do not change these without also changing jni_md.h in the JDK
+// repository
+#ifndef __has_attribute
+  #define __has_attribute(x) 0
+#endif
+#if (defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4) && (__GNUC_MINOR__ > 2))) || __has_attribute(visibility)
   #define JNIEXPORT     __attribute__((visibility("default")))
   #define JNIIMPORT     __attribute__((visibility("default")))
 #else

src/cpu/x86/vm/jni_x86.h

@@ -28,7 +28,13 @@
 
 #if defined(SOLARIS) || defined(LINUX) || defined(_ALLBSD_SOURCE)
 
-#if defined(__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4) && (__GNUC_MINOR__ > 2)
+
+// Note: please do not change these without also changing jni_md.h in the JDK
+// repository
+#ifndef __has_attribute
+  #define __has_attribute(x) 0
+#endif
+#if (defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4) && (__GNUC_MINOR__ > 2))) || __has_attribute(visibility)
   #define JNIEXPORT     __attribute__((visibility("default")))
   #define JNIIMPORT     __attribute__((visibility("default")))
 #else

src/cpu/zero/vm/jni_zero.h

@@ -25,7 +25,13 @@
  */
 
 
-#if defined(__GNUC__) && (__GNUC__ >= 4)
+
+// Note: please do not change these without also changing jni_md.h in the JDK
+// repository
+#ifndef __has_attribute
+  #define __has_attribute(x) 0
+#endif
+#if (defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4) && (__GNUC_MINOR__ > 2))) || __has_attribute(visibility)
   #define JNIEXPORT     __attribute__((visibility("default")))
   #define JNIIMPORT     __attribute__((visibility("default")))
 #else