display opt: mem size labels and minor segment reporting changes

for mem size labels: add one new "BUG" entry at the start of the array
  so `mem_size` does not need to be adjusted before being used to look
  up a string from the `MEM_SIZE_STRINGS` array. it's hard to measure
  the direct benefit of this, but it shrinks codegen size by a bit and
  simplfies a bit of assembly....

for segment reporting changes: stos/scas/lods do not actually need
  special segment override logic. instead, set their use of `es` when
  decoded, if appropriate. this is potentially ambiguous; in non-64bit
  modes the sequence `26aa` would decode as `stos` with explicit `es`
  prefix. this is now identical to simply decoding `aa`, which now also
  reports that there is an explicit `es` prefix even though there is no
  prefix on tne instruction.

  on the other hand, the prefix-reported segment now more accurately
  describes the memory selector through which memory accesses will
  happen. seems ok?

1 files changed, 2 insertions, 2 deletions

diff --git a/src/real_mode/display.rs b/src/real_mode/display.rs
index 9450a39..6472c6c 100644
--- a/src/real_mode/display.rs
+++ b/src/real_mode/display.rs
@@ -3436,7 +3436,7 @@ fn contextualize_intel<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors:
         }
 
         if x.is_memory() {
-            out.write_str(MEM_SIZE_STRINGS[instr.mem_size as usize - 1])?;
+            out.write_str(MEM_SIZE_STRINGS[instr.mem_size as usize])?;
             out.write_str(" ")?;
         }
 
@@ -3456,7 +3456,7 @@ fn contextualize_intel<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors:
                             out.write_str(", ")?;
                             let x = Operand::from_spec(instr, instr.operands[i as usize]);
                             if x.is_memory() {
-                                out.write_str(MEM_SIZE_STRINGS[instr.mem_size as usize - 1])?;
+                                out.write_str(MEM_SIZE_STRINGS[instr.mem_size as usize])?;
                                 out.write_str(" ")?;
                             }
                             if let Some(prefix) = instr.segment_override_for_op(i) {