[TimeZoneInfo] Fix issue with some floating DST transition times creating invalid DateTime values, and implement ToSerializedString and FromSerializedString.
This change is released under the MIT license.
Test Encoder.Convert and UTF8Encoder.Convert behaviors.
Added class ExposedEncoder to test the virtual method Encoder.Convert behavior.
Test UTF8Encoder.Convert override.
Add test for Regex.Match with anchors on a substring.
Regex fixes for substring parsing.
Miscellaneous changes per review
Add test for Regex RTL substring matching.
Added classes EncodingEncoder and EncodingDecoder.
EncodingEncoder and EncodingDecoder override Encoder.Convert.
The Convert overrides allow retrieval of chars/bytes buffers with the same size as .NET.
Merge pull request #1190 from esdrubal/encoder-convert

System.Text.Encoder convert
[ms.build] Do not try to release threads upon finalization.
[ms.build] Fix bug #20961 - add KeepDuplicates etc. to 4.0 as internal.

Since NET_4_0 and NET_4_5 share the same ToolsVersion (4.0) there seems no
way to distinguish the appropriate framework .targets file, so I ended up
to add the missing members as internal for 4.0.
[ms.build] add some cyclic dependency related tests (some are not working).
Merge pull request #1192 from LogosBible/regex-fixes-21803

Regex substring fix
[mcs] auto-property initializer can be array initializer
[mcs] Any type parameter is allowed for null propagating operator
[mcs] nameof operator
[corlib] Remove heavyweight EndsWith from 1bff9d890f95e72e4145d48980a05908c87b53ce
[System.Net.Http] Handle quoted filename value. Fixes #21960
Re-enable valid tests
[runtime] Fix logic when allocating code region if the first try at a fixed address fails.
[System] Implemented .NET 4.5 overloads for GZipStream and DeflateStream.

Fixes xambug #21982.