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, 1 insertions, 1 deletions

diff --git a/test/long_mode/mod.rs b/test/long_mode/mod.rs
index 8cb032c..b725287 100644
--- a/test/long_mode/mod.rs
+++ b/test/long_mode/mod.rs
@@ -2751,7 +2751,7 @@ fn only_64bit() {
     test_display(&[0xae], "scas byte es:[rdi], al");
     test_display(&[0xaf], "scas dword es:[rdi], eax");
     test_display(&[0x67, 0xaf], "scas dword es:[edi], eax");
-    test_display(&[0x67, 0xac], "lods al, byte ds:[esi]");
+    test_display(&[0x67, 0xac], "lods al, byte [esi]");
     test_display(&[0x67, 0xaa], "stos byte es:[edi], al");
     // note that rax.b does *not* change the register
     test_display(&[0x4f, 0xa0, 0x12, 0x34, 0x12, 0x34, 0x12, 0x34, 0x12, 0x34], "mov al, byte [0x3412341234123412]");