When we detect that a temporary variable is being reused
with a different type, we change the type of the temp
to dynamic.
This allows us to retain types for any non-reused temps.
For any dynamic temps we still have type information available
for use sites, which we can pass on via unsafeCast.
One drawback of this approach is that we don't know ahead
of time which temps are reused, and get turned into dynamic,
so we have to unsafeCast all uses.
This change is similar to what was done in:
https://dart-review.googlesource.com/c/sdk/+/138500
TEST=Adds tests/language/vm/regress_flutter_85311_test.dart,
updates relevant expect files.
Bug: https://github.com/flutter/flutter/issues/85311
Change-Id: I821c5266327892d5c3fd5bae1bebba7f3fe3931b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205647
Commit-Queue: Clement Skau <cskau@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Clement Skau
ffde1585da