`.align ABS-EXPR , ABS-EXPR'
============================

   Pad the location counter (in the current subsection) to a particular
storage boundary.  The first expression (which must be absolute) is the
number of low-order zero bits the location counter will have after
advancement.  For example `.align 3' will advance the location counter
until it a multiple of 8.  If the location counter is already a
multiple of 8, no change is needed.

   The second expression (also absolute) gives the value to be stored in
the padding bytes.  It (and the comma) may be omitted.  If it is
omitted, the padding bytes are zero.