This is mainly motivated by the March 2022 release of .NET 5. .NET 5 was
found to be vulnerable to CVE-2020-8927, which was caused by the older
version of brotli built into .NET. .NET was vulernable even in
environments where a system-wide version of brotli was present and had
already received fixes for this CVE. We could have avoided a Remote Code
Execution vulnerability in such environments by using the system's
version of brotli.

This is similar to the existing support for disabling distro-agnostic
OpenSSL (except no OpenSSL is embedded) and using the system libunwind
(a copy of libunwind is embedded this repo).

One small twist is the presence of entrypoint verification. In a
system-brotli build, the verification fails, because the built library,
libSystem.IO.Compression.Native.so, doesn't include the symbols for
Brotli. Those symbols are instead used from the system brotli libraries.

* Move brotli to src/native/external

* Move rapidjson to src/native/external

* Move zlib to src/native/external

* Move zlib-intel to src/native/external

* Cleanup trailing whitespace in changeset files

* Reorganize libs.native

* Fix darwin build

* Fix wasm-win32 build

* Fix pipelines path evaluation

* Unify ARRAY_SIZE/STRING_LENGTH-like macros

* Cleanup trailing whitespaces in changeset files

* Use ArrLen in the JIT

* Keep using G_N_ELEMENTS in mono

* Resolve name conflict in test

Co-authored-by: NElinor Fung <elfung@microsoft.com>

Adds support for RFC 7692 "compression extensions for websocket".

Closes #31088

* from prototype

* fix OSX

* fix for Android

* treat "libSystem.Globalization.Native" as QCall in mono too (for now).

* fix for wasm

* fix pedantic errors on GCC

* delete gPalGlobalizationNative

* pass overrider from the host

* default override

* default PInvoke override runs after optional host-provided overrider.

* Some PR feedback   (mostly related to code, not the CMake stuff).

* more coding PR feedback

* Deleted "libraries-native" folder.

* unifying tryrun.cmake into 1 common file

* factor out adding lib-specific dependencies into one place (per native library)

* cleanup: entirely remove tryrun.cmake propagation in eng, gen-buildsys, build-commons, and build scripts

* remove "clrcompression.dll" and "libSystem.IO.Compression.Native.dylib" from single-file host packaging

* mono: refactor Globalization lookup into `default_resolve_dllimport`.

* set FEATURE_DISTRO_AGNOSTIC_SSL according to __PortableBuild

* CORECLR_CALLING_CONVENTION for the host callback types

* refactor common parts of entrypoints.c into entrypoints.h

* rename OverrideEntry -->  DllImportEntry

* extra libs as CMake functions

* use macros instead of functions in extra_libs.cmake

* mono formatting style in src/mono/mono/metadata/native-library.c
Co-authored-by: NRyan Lucia <ryan@luciaonline.net>

* mono: Remaining stylistic nits.
Co-authored-by: NRyan Lucia <ryan@luciaonline.net>

* do not set DFEATURE_DISTRO_AGNOSTIC_SSL on iOS, Android, tvOS
Co-authored-by: NRyan Lucia <ryan@luciaonline.net>