[sh4] Introduce const pools in LLINT.

https://bugs.webkit.org/show_bug.cgi?id=122746

Patch by Julien Brianceau <jbriance@cisco.com> on 2013-10-15
Reviewed by Michael Saboff.

In current implementation of LLINT for sh4, immediate values outside range -128..127 are
loaded this way:

    mov.l .label, rx
    bra out
    nop
    .balign 4
    .label: .long immvalue
    out:

This change introduces const pools for sh4 implementation to avoid lots of useless branches
and reduce code size. It also removes lines of dirty code, like jmpf and callf.

* offlineasm/instructions.rb: Remove jmpf and callf sh4 specific instructions.
* offlineasm/sh4.rb:

Change-Id: Ieeceaaa5eb55ab9439d923afccceb783e9930ee4
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@157452 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>