There was only one user. It's "condition" argument was used
for "ia" rather than an actual condition. The apcs26 syntax
is almost certainly not needed, given current binutils requirements.
Some routines are written with complex LDM/STM insns that cannot be
used in thumb mode, or are highly conditional requiring excessive
IT insns.
When a future patch goes in to enable thumb2 by default, this marker
will be used to override that default.
Joseph Myers
Roland McGrath
Richard Henderson