Make it possible to supply compilation units from plugins

This also cleans up the script and type initialization in
the type loader, for example by getting rid of the m_irUnit
member for scripts.

Change-Id: I207afeb21c0bae9091d3c7b4cac2e80e9aae0ea3
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Remove dead code

Remove qquick anchor line comparison hooks, which were intended to be used
inside the old v4 interpreter (but that was incomplete) and are now completely
unused.

Change-Id: I06b0dd684a292adb44efa52d27258242954285ee
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Eliminate noop translation bindings

We can store them as regular strings. This has the advantage that the
entire special handling from the custom parser of the list model goes away,
we don't need astForBinding in QQmlCustomParser anymore neither and types
with a custom parser can now generally benefit from the expression simplification
pass.

Change-Id: I39d1b76edd1273d8c73b847aed71f7bcce37d877
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Remove object index parameter from QQmlCustomParser::compile

There is no need anymore to pass through the object index of the
object being "custom compiled".

Change-Id: I8ef8e578b27523d9e7190503fbf95d1eb863a149
Reviewed-by: Lars Knoll <lars.knoll@digia.com>