[memory barrier] use pagesize determined by helper (#18396)
commita83bdec08e8c822f2ad50e6c8192519479f4c260
authormonojenkins <jo.shields+jenkins@xamarin.com>
Fri, 10 Jan 2020 00:55:45 +0000 (10 01:55 +0100)
committerGitHub <noreply@github.com>
Fri, 10 Jan 2020 00:55:45 +0000 (10 01:55 +0100)
treea05430fbe3fba2faec115d28dbdd97cbd4091843
parentf323b29968f251989139b986a36a30200ffb4fa6
[memory barrier] use pagesize determined by helper (#18396)

[2019-12] [memory barrier] use pagesize determined by helper

`limits.h` doesn't always define `PAGESIZE` properly (e.g. iOS), so it would fall back to `0x1000` (4096) but it's really `0x4000` (16384) on iOS. We already have a helper in the runtime to determine the pagesize, so let's use that instead.

Fixes https://github.com/mono/mono/issues/18273

Backport of #18383.

/cc @lewurm
mono/utils/mono-threads-posix.c