This reverts commit r203374.
Ambiguities in assign... oh well. I'm just going to revert this and
probably not try to recommit it as it's not terribly important.
llvm-svn: 203375
Move a common utility (assign(iter, iter)) into SmallVector (some of the
others could be moved there too, but this one seemed particularly
generic) and replace repetitions overrides with using directives.
And simplify SmallVector::assign(num, element) while I'm here rather
than thrashing these files (that cause everyone to rebuild) again.
llvm-svn: 203374