* ARC backend accepts .extInstruction, .extCondCode, .extAuxRegister, and
.extCoreRegister pseudo-ops that allow an user to define custom
instructions, conditional codes, auxiliary and core registers.
* ARC backend accepts .extInstruction, .extCondCode, .extAuxRegister, and
.extCoreRegister pseudo-ops that allow an user to define custom
instructions, conditional codes, auxiliary and core registers.