Add release notes

Author: rnk

clang/docs/ReleaseNotes.rst

@@ -332,6 +332,11 @@ Non-comprehensive list of changes in this release
 - Clang no longer rejects reinterpret_cast conversions between indirect
   ARC-managed pointers and other pointer types. The prior behavior was overly
   strict and inconsistent with the ARC specification.
+- On non-Windows platforms, Clang now builds as a large shared library,
+  ``libclang-cpp``, by default. To revert to the old behavior of producing and
+  linking static libraries, pass ``-DCLANG_LINK_CLANG_DYLIB=OFF`` to CMake when
+  configuring your build. The new behavior matches LLVM, which also builds as a
+  large shared library.
 
 New Compiler Flags
 ------------------

llvm/docs/ReleaseNotes.md

@@ -90,7 +90,7 @@ Changes to LLVM infrastructure
 Changes to building LLVM
 ------------------------
 
-* On non-Windows platforms, LLVM now builds as a large shared library, libLLVM,
+* On non-Windows platforms, LLVM now builds as a large shared library, `libLLVM`,
   by default. To revert to the old behavior of producing and linking static
   libraries, pass ``-DLLVM_LINK_LLVM_DYLIB=OFF`` to CMake when configuring your
   build.