For each selector, count the number of calls to the selector that are
both reachable and polymorphic according to the TFA. Only include
selectors in the table with non-zero counts.
This reduces the dispatch table size by 30% in dart2js and by 49% in
Flutter Gallery (312k memory use reduction on ARM64).
Call counts are transferred in a dedicated metadata block with
per-selector information. This mechanism also prepares for transferring
other per-selector information in the future.
Change-Id: Iba15aa4d6c50e67e53c3fd8e542123d3fc98bd07
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/132603
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Aske Simon Christensen
1c2d378068