Before this change we would systematically call LQueries.clone() when executting
elementStart / elementContainerStart instructions. This was often unnecessary as
LQueries can be mutated under 2 conditions only:
- we are crossing an element that has directives with content queries
(new queries must be added);
- we are descending into element hierarchy (creating a child element of an existing element)
and the current LQueries object is tracking shallow queries (shallow queries are removed).
With this PR LQueires.clone() is only done when needed and this gratelly reduces number
of LQueries object created: in the "expanding rows" benchmark number of allocated
(and often GCed just after!) LQueries is reduced from ~100k -> ~35k. This represents
over 1MB of memory that is not allocated.
PR Close#30664
8154433130