Documentation: convert ReleaseNotes.html to reST.

Patch by Anthony Mykhailenko with small fixes by me.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169714 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/CodeGenerator.rst b/docs/CodeGenerator.rst
index cafa93e..ce23667 100644
--- a/docs/CodeGenerator.rst
+++ b/docs/CodeGenerator.rst
@@ -1732,6 +1732,8 @@
 specific to the code generator for a particular target.  First we start with a
 table that summarizes what features are supported by each target.
 
+.. _target-feature-matrix:
+
 Target Feature Matrix
 ---------------------