bpo-42972: Fully support GC for mmap heap types (GH-26373)

(cherry picked from commit 318adeba780851c416505e48a3454cacca831419)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Miss Islington (bot) committed 5y ago

da8097aaf5a55c23f5b5ddbeffc2d90d06e00d93

Parent: e73b3b1

Committed by GitHub <noreply@github.com> on 5/27/2021, 4:43:56 PM