Fixed small bugs/issues

- In 'readutf8esc' (llex.c), the overflow check must be done before
shifting the accumulator. It was working because tests were using
64-bit longs. Failed with 32-bit longs.

- In OP_FORPREP (lvm.c), avoid negating an unsigned value. Visual
Studio gives a warning for that operation, despite being well
defined in ISO C.

- In 'luaV_execute' (lvm.c), 'cond' can be defined only when needed,
like all other variables.
2 files changed