[GWP-ASan] Add GWP-ASan information to tombstones.

GWP-ASan can provide information about a crash that it caused. Grab the
GWP-ASan regions from the globals shared by the linker for crash-handler
purpopses, pull the information from GWP-ASan, and display it.

This adds two regions:
 1. Causality tracking by GWP-ASan. We now print a cause header about
 the crash, like `Cause: [GWP-ASan]: Use After Free on a 1-byte
 allocation at 0x7365bb3ff8`
 2. Allocation and deallocation stack traces.

Bug: 135634846
Test: atest debuggerd_test

Change-Id: Id28d5400c9a9a053fcde83a4788f971e677d4643