Summary:
Fuchsia wants to use mutexes with PI in the Scudo code, as opposed to
our own implementation. This required making `lock` & `unlock` platform
specific (as opposed to `wait` & `wake`) [code courtesy of John
Grossman].
There is an additional flag required now for mappings as well:
`ZX_VM_ALLOW_FAULTS`.
Reviewers: morehouse, mcgrathr, eugenis, vitalybuka, hctim
Reviewed By: morehouse
Subscribers: delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D63435
llvm-svn: 363705