#514 mcs51: Prevent mixed jump sizes in jump tables

[Li-Hsin Chien]

Fixes [bugs:#4066]:

Peephole 260.i changes all jump table entries to 2-byte sjmp instructions and uses index * 2 to find an entry.
Later, peephole 257.b changes some of them back to 3-byte ljmp instructions.
The entries then have different sizes, this can cause a jump to the wrong location.

This patch adds notInJumpTable() to peephole 257.b so it does not change instructions inside a jump table.

I tested the original failing testcase with the same random configuration, and it now passes.

[Li-Hsin Chien]

Updated: bug-4066-v2.patch

The actual code change is unchanged. I only added a regression test
based on the original failing gcc-torture-execute-20011109-1.c testcase.

Please use this version instead of the previous one!

[Li-Hsin Chien]

ChangeLog:

* src/mcs51/peeph.def (257.b): Do not apply this rule inside jump
  tables.
* support/regression/tests/bug-4066.c: New regression test.

[Maarten Brock]

Applied in [r16836]. Thanks!