Heap references always point into R/RW mapping (this simplifies the
marker) and entry points are retargeted into RX.
To simplify implementation we assume that there are no image pages
created - which means we can always go from Instructions to the start of
the page and check where it is dual mapped to.
TEST=vm/dart/macos_dual_mapping_smoke_test and manually on physical
device
Change-Id: Idbe02b7b695b3c048072cf92f7d062f5ab6e1beb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/433940
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Vyacheslav Egorov
d194fcecaf