Update changelog for 0.21.0-insiders. (#2794)

Author: sean-mcmanus

Extension/CHANGELOG.md

@@ -1,5 +1,14 @@
 # C/C++ for Visual Studio Code Change Log
 
+## Version 0.21.0-insiders: November 8, 2018
+* Add support for `__int128_t` and `__uint128_t` types. [#1815](https://github.com/Microsoft/vscode-cpptools/issues/1815)
+* Fix for several incorrect IntelliSense error squiggles. [#1942](https://github.com/Microsoft/vscode-cpptools/issues/1942), [#2478](https://github.com/Microsoft/vscode-cpptools/issues/2478), [#2763](https://github.com/Microsoft/vscode-cpptools/issues/2763)
+* Fix for several crashes. [#2505](https://github.com/Microsoft/vscode-cpptools/issues/2505), [#2768](https://github.com/Microsoft/vscode-cpptools/issues/2768)
+* Fix completion not working in template specializations. [#2620](https://github.com/Microsoft/vscode-cpptools/issues/2620)
+* Fix memory "leak" when parsing a large workspace. [#2737](https://github.com/Microsoft/vscode-cpptools/issues/2737)
+* Fix `Go to Definition` when `__catch()`, `_NO_EXCEPT_DEBUG`, or `_LIBCPP_BEGIN_NAMESPACE_STD` is used. [#2761](https://github.com/Microsoft/vscode-cpptools/issues/2761), [#2766](https://github.com/Microsoft/vscode-cpptools/issues/2766)
+* Fix compiler in `compile_commands.json` not taking precedence over the `Cpp.default.compilerPath`. [#2793](https://github.com/Microsoft/vscode-cpptools/issues/2793)
+
 ## Version 0.20.1: October 31, 2018
 * Fix IntelliSense-based `Go to Declaration` when there's only a definition in a TU. [#2743](https://github.com/Microsoft/vscode-cpptools/issues/2743)
 * Fix `#include` completion for standalone header files. [#2744](https://github.com/Microsoft/vscode-cpptools/issues/2744)