Improve process_ea and introduce -OL

Two fixes:
1. Optimization of [bx+0xFFFF] etc
   0xFFFF is an sbyte under 16-bit semantics,
   so make sure to check it right.

2. Don't optimize displacements in -O0
   Displacements that fit into an sbyte or
   can be removed should *not* be optimized in -O0.

   Implicit zero displacements are still optimized, e.g.:
   [eax] -> 0 bit displacement, [ebp] -> 8 bit displacement.
   However explicit displacements are not optimized:
   [eax+0] -> 32 bit displacement, [ebp+0] -> 32 bit displacement.

Because #2 breaks compatibility with 0.98,
I introduced a new optimization level: -OL, legacy.

1 files changed, 1 insertions, 0 deletions

diff --git a/parser.c b/parser.c
index ea36e86..4585a5b 100644
--- a/parser.c
+++ b/parser.c
@@ -804,6 +804,7 @@ is_expression:
                     }
                 }
             } else {
+                result->oprs[operand].eaflags |= EAF_NO_OFFS;
                 o = 0;
                 result->oprs[operand].wrt = NO_SEG;
                 result->oprs[operand].segment = NO_SEG;