fix bugs of softice.ASM, "Execution Timing", and "Guard Pages".

I fixed the following problems.
- softice.ASM does not set a exception handler.
  And, Flat Assembler generates "icebp" from "int1" mnemonic.
- Execution Timing tests calculate "initial - end".
- Guard Pages test does not jump to the allocated pages.
Merge pull request #1 from yotuki/fixbugs

fix bugs of softice.ASM, "Execution Timing", and "Guard Pages".