109d963bf9
The range of Smis must be reduced so that pointer compression is not lossy.
Smis are kept in sign-extended form. In the future, we might track down all places that perform Smi comparisons or otherwise assume sign-extension. Allowing garbage in the upper half would make it safe to unconditionally add the heap base during pointer decompression.
Based on cf78da8a48.
TEST=ci
Change-Id: If8c76da3166c170618e5b3f3991353bab5c84e6f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181760
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Liam Appelbe <liama@google.com>