commit 356bd28feeedeb24e1f458492fdc5ecaef39c1eb
author Vladimir Marko <vmarko@google.com> Wed Mar 01 12:01:11 2017 +0000
committer Vladimir Marko <vmarko@google.com> Mon Mar 13 18:05:45 2017 +0000
tree e68b917d6c7ae3347baa74dea279a8681b0626a7
parent d1d4530ffa97729aa8944932a7ac2009ae51c7e3

Introduce EnvUsePosition for liveness analysis.

Normal and environment use positions are held in separate
lists and the code never mixes them together. By using two
separate classes, we can reduce complexity and avoid an
unnecesary data member, reducing the memory usage.

Tracking allocations for a certain big app, the peak arena
memory usage is
  before:
    MEM: used: 79245960, ...
    SsaLiveness    31221600
  after:
    MEM: used: 78754024, ...
    SsaLiveness    30729664

Test: testrunner.py --host
Bug: 34053922
Change-Id: I02d3c9f564bbe3b1da0e03c33cf7c0f810f235dc