[GWP-ASan] 32-bit test pointers, allow multi-init for test.

Authored by hctim on Dec 9 2019, 8:19 AM.


[GWP-ASan] 32-bit test pointers, allow multi-init for test.

GWP-ASan test currently fail on 32-bit platforms, as some of the pointers are
larger than uintptr_t on 32-bit platforms. Fix up all those instances.

Also add an uncompress varint test where the result is an underflow.

Furthermore, allow multi-init for testing. Each gtest when running
check-gwp_asan apparently runs in its own instance, but when integrating
these tests into Android, this behaviour isn't the same. We remove the
global multi-init check here, to allow for testing to work elsewhere, and we're
not really worried about multi-init anyway as it's part of our contract with
the allocator.

Reviewers: eugenis, vlad.tsyrklevich

Reviewed By: eugenis

Subscribers: #sanitizers, llvm-commits, pcc

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D71121