* src/vm/jit/s390/codegen.h: Added functions for instruction parsing and manipulation...

* src/vm/jit/s390/codegen.h: Added functions for instruction parsing and manipulation, added opcode defines.
* src/vm/jit/s390/codegen.c (codegen_emit): Replaced handcrafted machined code patching by marco.
* src/vm/jit/s390/emit.c (emit_branch): Likewise.
* src/vm/jit/s390/md.c (md_jit_method_patch_address, md_signal_handler_sigsegv, md_signal_handler_sigill, md_signal_handler_sigfpe): Replaced handcrafted machine code parsing and patching by calls to new functions.
* src/vm/jit/s390/patcher.c (patcher_invokeinterface, patcher_invokevirtual, patcher_get_putfield): Likewise.