s390: c1/c2 fail to add a metadata relocation in the static call stub.

The test vmTestbase/nsk/jvmti/RedefineClasses/StressRedefine non-deterministically crashes the vm on s390.

Analysis:

- c1/c2 generates static call stub without metadata relocation for the instruction L that loads the target Method* T
  into Z_method.
  (see LIR_Assembler::emit_static_call_stub(), CompiledStaticCall::emit_to_interp_stub(), MacroAssembler::load_const_from_toc())

- During call resolution the initialization of T in the metadata pool fails silently because no
  metadata relocation for L is found.
  Note that the load does not load from the metadata pool, but from the toc, which is accurately updated.
  (see CompiledDirectStaticCall::set_to_interpreted(), NativeMovConstReg::set_data(), relocInfo::update_oop_pool())

- T is not marked 'on-stack' during class redefinition, because it is not found in the metadata pool of the caller
  (see MetadataOnStackMark, nmethod::metadata_do())

- Metadata of T (e.g. constant pool) is reclaimed, because T was redefined.

- static stub referencing T is executed and VM crashes