* src/vm/jit/codegen-common.cpp (codegen_emit): New generic version of the

* src/vm/jit/codegen-common.cpp (codegen_emit): New generic version of the
code generating loop. This is the main point of this huge commit.

There are some other changes which might be interesting about this commit,
which are described in detail:
* src/vm/jit/code.hpp (codeinfo): Added runtime information to replace most
parts of the method header.
* src/vm/jit/codegen-common.cpp (codegen_finish): Sets runtime information.
(codegen_start_native_call): Use MD function to determine size of stackframe.
(codegen_finish_native_call): Likewise.
* src/vm/jit/codegen-common.hpp: Added prototypes of new MD functions.
* src/vm/jit/emit-common.hpp: Added prototypes of new MD functions.
(emit_xmove): Added generic inline functions for register moves.
* src/vm/jit/optimizing/profile.c: Disabled some broken profiling code.
* src/vm/jit/optimizing/profile.h: Moved definitions CPU cycle counting
macros to where they belong.
* src/vm/jit/replace.cpp: Uses new architecture description macros.
* src/vm/jit/stacktrace.cpp: Use MD function to determine size of stackframe.

The rest of the files were machine dependent adaptions of the different ports
with too many changes to describe here, so I just list the files:
* src/vm/jit/alpha/arch.h
* src/vm/jit/alpha/codegen.c
* src/vm/jit/alpha/codegen.h
* src/vm/jit/alpha/emit.c
* src/vm/jit/alpha/md.h
* src/vm/jit/arm/arch.h
* src/vm/jit/arm/codegen.c
* src/vm/jit/arm/codegen.h
* src/vm/jit/arm/emit.c
* src/vm/jit/arm/md.h
* src/vm/jit/i386/arch.h
* src/vm/jit/i386/codegen.c
* src/vm/jit/i386/codegen.h
* src/vm/jit/i386/emit.c
* src/vm/jit/i386/emit.h
* src/vm/jit/i386/md.h
* src/vm/jit/m68k/arch.h
* src/vm/jit/m68k/codegen.c
* src/vm/jit/m68k/codegen.h
* src/vm/jit/m68k/emit.c
* src/vm/jit/m68k/md.h
* src/vm/jit/mips/arch.h
* src/vm/jit/mips/codegen.c
* src/vm/jit/mips/codegen.h
* src/vm/jit/mips/emit.c
* src/vm/jit/mips/md.h
* src/vm/jit/powerpc/arch.h
* src/vm/jit/powerpc/codegen.c
* src/vm/jit/powerpc/codegen.h
* src/vm/jit/powerpc/emit.c
* src/vm/jit/powerpc/md.h
* src/vm/jit/powerpc64/arch.h
* src/vm/jit/powerpc64/codegen.c
* src/vm/jit/powerpc64/codegen.h
* src/vm/jit/powerpc64/emit.c
* src/vm/jit/powerpc64/md.h
* src/vm/jit/s390/arch.h
* src/vm/jit/s390/codegen.c
* src/vm/jit/s390/codegen.h
* src/vm/jit/s390/emit.c
* src/vm/jit/s390/md.h
* src/vm/jit/sparc64/arch.h
* src/vm/jit/sparc64/codegen.c
* src/vm/jit/sparc64/codegen.h
* src/vm/jit/sparc64/emit.c
* src/vm/jit/sparc64/md.h
* src/vm/jit/x86_64/arch.h
* src/vm/jit/x86_64/codegen.c
* src/vm/jit/x86_64/codegen.h
* src/vm/jit/x86_64/emit.c
* src/vm/jit/x86_64/emit.h
* src/vm/jit/x86_64/md.h