Fix race between dex-file registration and class-loader deletion

We keep track of class-loaders by having a list with jweak references
to the dex-caches. When we register a new dex-file we check that the
dex-cache hasn't already been registered with a different
class-loader. We decoded the jweak and performed this check this
without any locks however meaning we could race with class-loader
cleanup. This could cause CHECK failures as we try to decode a deleted
jweak.

Bug: 147206162
Test: ./art/test/run-test --create-runner   --host --prebuild --compact-dex-level fast --optimizing --no-relocate --runtime-option -Xcheck:jni  2001-virtual-structural-multithread
      ./art/tools/parallel_run.py
Merged-In: Ibeb12ec3d42f7972d09b155b7c24743266897a54
Change-Id: Ibeb12ec3d42f7972d09b155b7c24743266897a54
(cherry picked from commit dc91717ad17d79ba50bafec4340000ebfcb7a366)

0 files changed, 0 insertions, 0 deletions