Issue ceylon/ceylon-compiler#1382: Revert "AbstractIterable: Figure out an initial size for the SequenceBuilder when"

This reverts commit bdb2d430e8c68a2a44faaa148db40bec23bd650f.

Conflicts:
	runtime/ceylon/language/integerRangeByIterable_.java
	runtime/com/redhat/ceylon/compiler/java/language/AbstractIterable.java