* Update branding to 3.1.17 (#28173)

* Port from 5.0: Fix Position Independent Code in CMake files (#28143)

* CoreCLR PR26323 Port: Fix PIE options

* Added missing PIE and RELRO compilation flags.

* Merged PR 15832: Port from 5.0: Fix Position Independent Code in CMake files (#28143)

Port from 5.0: Fix Position Independent Code in CMake files (#28143)

* CoreCLR PR26323 Port: Fix PIE options

* Added missing PIE and RELRO compilation flags.

* Fix System.Globalization.Native build on Big Sur (#28181)

* Fix System.Globalization.Native build on Big Sur

* Fix build

* Add flags for Linux

* [release/3.1] Handle Counter Polling Interval of 0 (#28180)

* Backport  dotnet/runtime#53836

* Fix test build

* update test

* update branding to 3.1.18 (#28182)

* Update dependencies from https://github.com/dotnet/core-setup build 20210609.1 (#28178)

Microsoft.NETCore.App
 From Version 3.1.9-servicing.20459.3 -> To Version 3.1.17-servicing.21309.1

Co-authored-by: dotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>

* Merged PR 15716: [release/3.1] Use user read+write access for coredump file descriptor open

* [release/3.1] #28183 Fix OSX native dependency installation

* Avoid upgrading packages that are explicitly installed.
* Use a brewfile
* Change shebang to use bash and directly execute.

* [release/3.1] Update dependencies from dotnet/corefx (#28179)

[release/3.1] Update dependencies from dotnet/corefx


 - Add 3.1 AzDO feeds to the test build to ensure that the test build can correctly restore the CoreFX build.

It seems that the new CoreFX build isn't on the old blob feeds, so without this fix, we end up restoring the first 5.0.0-alpha.1 build instead of the build we want.

 - Exclude tests that depend on OOB assemblies.

 - Turn off CoreFX test legs in CI.

Now that the branch is on servicing, and the churn is low, exclude these as they
break far more often than they detect issues. These already run in CoreFX CI on release bits.
In case we want to bring them back for checked testing, we need to fix CoreFX.depproj.
It has a package - Microsoft.Private.CoreFx.OOB - that's supposed to bring in all deps
that are out of box. These are currently not getting restored and this ends up causing
File not found issues in the binder when compiling tests, making test exclusions impossible.
Please enter the commit message for your changes. Lines starting
with '#' will be ignored, and an empty message aborts the commit.

Co-authored-by: Jan Jahoda <jajahoda@microsoft.com>
Co-authored-by: Ivan Diaz Sanchez <ivdiazsa@microsoft.com>
Co-authored-by: Will Godbe <wigodbe@microsoft.com>
Co-authored-by: Santiago Fernandez Madero <safern@microsoft.com>
Co-authored-by: John Salem <josalem@microsoft.com>
Co-authored-by: Anirudh Agnihotry <anirudhagnihotry098@gmail.com>
Co-authored-by: dotnet-bot <dotnet-bot@microsoft.com>
Co-authored-by: dotnet-maestro[bot] <42748379+dotnet-maestro[bot]@users.noreply.github.com>
Co-authored-by: dotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>