Preventing x86 instruction length optimizations

[Florian Weimer]

A recent GAS update to Debian (currently at 2.16.1cvs20050902-1)
changed the length of this instruction:

  adc 0(%ebx,%ecx,4),%edx

Previously, it was encoded as a four-octet sequence, now it's
equivalent to:

  adc (%ebx,%ecx,4),%edx

-- which only needs three octets.

Is this the intended behavior?  Is there any easy way to force the
long instruction encoding, short of using .byte?