Grow heap aggressively during music interpretation (issue 561390043 by hanwenn@gmail.com)

[lemzwerg--- via Discussions on LilyPond development]

LGTM


https://codereview.appspot.com/561390043/diff/563450046/lily/score-engraver.cc
File lily/score-engraver.cc (right):

https://codereview.appspot.com/561390043/diff/563450046/lily/score-engraver.cc#newcode200
lily/score-engraver.cc:200: // This double the heap. TODO: don't do this
if we get close to
s/double/doubles/

https://codereview.appspot.com/561390043/