Ben Gamari authored May 11, 2017 and Ben Gamari committed May 11, 2017

StgCRunAsm.S provides StgCRun on powerpc64le platforms when
registerised.  However, in the unregisterised setting we use the
mini-interpreter and consequently shouldn't build StgCRunAsm.S lest we
get duplicate symbols.

Test Plan: Build unregisterised compiler on AIX.

Reviewers: hvr, trommler, austin, simonmar

Reviewed By: trommler, simonmar

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3560