Implementation on a JIT compiler

We implemented Golliver's technique on shuJIT.
To implement on a JIT is, in other words, making the compiler generate native code which satisfy the specification.

Modifications to shuJIT
We introduced internal opcodes for `strictfp'.
For mult. and div.:   fmul_strict, dmul_strict, fdiv_strict, ddiv_strict
And provided pre-assembled native code for these instructions.
The JIT translates bytecode insns. to corresponding internal insns., and generate native code for them.
We provided two options:
frcstrictfp (force) and ignstrictfp (ignore).
Useful in examining performance of existing programs.