Update changelog

CHANGES.txt

@@ -26,6 +26,17 @@
   * Save code space by avoiding inlining of large-in-aggregate code-space MessageLite::~MessageLite destructor.
   * Breaking change: delete Arena::Init
   * Make a PROTOBUF_POISON/UNPOISON to reduce noise in the source
+  * Put alignment functions in "arena_align.h"
+  * Split off `cleanup` arena functions into "arena_cleanup.h"
+  * Fix signed / unsigned match in CHECK_EQ
+  * Kill Atomic<>. it's not pulling it's weight
+  * Move AllocationPolicy out of arena_impl, and unify arena_config for bazel
+  * Fix failure case in table-driven parser.
+  * Add a new JSON parser.
+  * Removed old JSON parsing code.
+  * Introduce the Printer::{SetRedactDebugString,SetRandomizeDebugString} private flags.
+  * Introduce global flags to control Printer::{SetRedactDebugString, SetRandomizeDebugString}.
+  * proto3 string fields no longer trigger clang-tidy warning bugprone-branch-clone.
 
 
   Kotlin
@@ -41,11 +52,17 @@
   * More thoroughly annotate public generated code in Java lite protocol buffers.
   * Fixed Bug in proto3 java lite repeated enum fields. Failed to call copyOnWrite before modifying previously built message. Causes modification to already "built" messages that should be immutable.
   * Fix Java reflection serialization of empty packed fields.
+  * Refactoring java full runtime to reuse sub-message builders and prepare to migrate parsing logic from parse constructor to builder.
+  * Fix TextFormat parser to build up recurring (but supposedly not repeated) sub-messages directly from text rather than building a new sub-message and merging the fully formed message into the existing field.
+  * Make message-type extensions merge from wire-format instead of building up instances and merging afterwards. This has much better performance.
+  * Change the Lite runtime to prefer merging from the wireformat into mutable messages rather than building up a new immutable object before merging. This way results in fewer allocations and copy operations.
+  * Move proto wireformat parsing functionality from the private "parsing constructor" to the Builder class.
 
   Python
   * Changes ordering of printed fields in .pyi files from lexicographic to the same ordering found in the proto descriptor.
   * Adds GeneratedCodeInfo annotations to python proto .pyi outputs as a base64 encoded docstring in the last line of the .pyi file for code analysis tools.
   * Fix message factory's behavior in python cpp extension to return same message classes for same descriptor, even if the factories are different.
+  * Add type annotation for enum value fields in enum classes.
 
   Compiler
   * Print full path name of source .proto file on error