Updated CHANGES.txt for 3.16.0 (#8456)

* Updated CHANGES.txt for 3.16.0

* Fix spelling errors

Author: acozzette

.github/workflows/codespell.yml

@@ -13,4 +13,4 @@ jobs:
         with:
           check_filenames: true
           skip: ./.git,./conformance/third_party,*.snk,*.pb,*.pb.cc,*.pb.h,./src/google/protobuf/testdata,./objectivec/Tests,./python/compatibility_tests/v2.5.0/tests/google/protobuf/internal
-          ignore_words_list: "alow,alse,ba,cleare,copyable,cloneable,dedup,dur,errorprone,files',fo,fundementals,hel,importd,inout,leapyear,nd,nin,ois,ons,parseable,process',te,testof,ue,unparseable,wasn,wee,gae,keyserver,objext,od,OptIn"
+          ignore_words_list: "alow,alse,ba,cleare,copyable,cloneable,dedup,dur,errorprone,files',fo,fundementals,hel,importd,inout,leapyear,nd,nin,ois,ons,parseable,process',te,testof,ue,unparseable,wasn,wee,gae,keyserver,objext,od,optin"

CHANGES.txt

@@ -1,6 +1,20 @@
-Unreleased Changes (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
+2021-04-06 version 3.16.0 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
 
   C++
+  * Fix compiler warnings issue found in conformance_test_runner #8189 (#8190)
+  * Fix MinGW-w64 build issues. (#8286)
+  * [Protoc] C++ Resolved an issue where NO_DESTROY and CONSTINIT are in incorrect order (#8296)
+  * Fix PROTOBUF_CONSTINIT macro redefinition (#8323)
+  * Delete StringPiecePod (#8353)
+  * Fix gcc error: comparison of unsigned expression in '>= 0' is always … (#8309)
+  * Fix cmake install on iOS (#8301)
+  * Create a CMake option to control whether or not RTTI is enabled (#8347)
+  * Fix endian.h location on FreeBSD (#8351)
+  * Refactor util::Status (#8354)
+  * Make util::Status more similar to absl::Status (#8405)
+  * Fix -Wsuggest-destructor-override for generated C++ proto classes. (#8408)
+  * Refactor StatusOr and StringPiece (#8406)
+  * Refactor uint128 (#8416)
   * The ::pb namespace is no longer exposed due to conflicts.
   * Allow MessageDifferencer::TreatAsSet() (and friends) to override previous
     calls instead of crashing.
@@ -25,20 +39,47 @@ Unreleased Changes (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
   * util::DefaultFieldComparator will be final in a future version of protobuf.
     Subclasses should inherit from SimpleFieldComparator instead.
 
-  Java:
+  C#
+  * Add .NET 5 target and improve WriteString performance with SIMD (#8147)
+
+  Java
+  * deps: update JUnit and Truth (#8319)
   * Detect invalid overflow of byteLimit and return InvalidProtocolBufferException as documented.
   * Exceptions thrown while reading from an InputStream in parseFrom are now
     included as causes.
   * Support potentially more efficient proto parsing from RopeByteStrings.
   * Clarify runtime of ByteString.Output.toStringBuffer().
+  * Added UnsafeByteOperations to protobuf-lite (#8426)
+
+  JavaScript
+  * Make Any.pack() chainable.
 
   Python
+  * Fix some constness / char literal issues being found by MSVC standard conforming mode (#8344)
+  * Switch on "new" buffer API (#8339)
+  * Enable crosscompiling aarch64 python wheels under dockcross manylinux docker image (#8280)
   * Fixed a bug in text format where a trailing colon was printed for repeated field.
   * When TextFormat encounters a duplicate message map key, replace the current
     one instead of merging.
 
-  JavaScript
-  * Make Any.pack() chainable.
+  Objective-C
+  * Move the class map to a CFDictionary. (#8328)
+
+  PHP
+  * read_property() handler is not supposed to return NULL (#8362)
+  * Changed parameter type from long to integer (#7613)
+  * fix: README supported PHP version for C extension (#8236)
+
+  Ruby
+  * Fixed quadratic memory usage when appending to arrays. (#8364)
+
+  Other
+  * Some doc on AOT compilation and protobuf (#8294)
+  * [CMake] Ability to pass options to protoc executable from cmake (#8374)
+  * Add --fatal_warnings flag to treat warnings as errors (#8131)
+  * [bazel] Remove deprecated way to depend on googletest (#8396)
+  * add error returns missing from protoc to prevent it from exiting with… (#8409)
+
 
 2021-04-02 version 3.15.7 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)