CR 8075955: "Replace the macro based implementation of oop_oop_iterate with a template based solution" changed src/share/vm/oops/instanceKlass.inline.hpp and replaced macro based oop iteration by templates.

For performance reason, the change (and a follow up change for Oracle Studio) introduced forcing of inlining for some places in src/share/vm/oops/instanceKlass.inline.hpp, see:

http://hg.openjdk.java.net/jdk9/dev/hotspot/file/797e6aac6d53/src/share/vm/oops/instanceKlass.inline.hpp

....
// The iteration over the oops in objects is a hot path in the GC code.
// By force inlining the following functions, we get similar GC performance
// as the previous macro based implementation.
#ifdef TARGET_COMPILER_visCPP
#define INLINE __forceinline
#elif defined(TARGET_COMPILER_sparcWorks)
#define INLINE __attribute__((always_inline))
#else
#define INLINE inline
#endif
....

We can do this on AIX as well, as xlC also supports the 'always_inline' compiler attribute. See:

http://www.ibm.com/support/knowledgecenter/SSGH2K_12.1.0/com.ibm.xlc121.aix.doc/language_ref/function_attributes.html?lang=en