This allows the customary syntax for declaring named arguments,
such as:
asm ("mov %[out],%[in]" : [out] "=r" (x) : [in] "r" (y));
Since :[ is comple-error-inducingly invalid syntax in other cases,
this won't create unintentional leniency for normal uses of [
Originally from https://lkml.org/lkml/2010/11/16/145 by Dave Martin
Change-Id: Iead3fdb147ba2f6cbd108f19dd348bb72a7e6b6f
Signed-off-by: Anas Nashif <anas.nashif@intel.com>