[mips] Added release notes for 3.6.1.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_36@236417 91177308-0d34-0410-b5e6-96231b3b80d8

docs/ReleaseNotes.rst

@@ -25,6 +25,32 @@ them.
 Non-comprehensive list of changes in this release
 =================================================
 
+Changes to the MIPS Target
+--------------------------
+
+* Added support for 128-bit integers on 64-bit targets.
+
+* Fixed some remaining N32/N64 calling convention bugs when using small
+  structures on big-endian targets.
+
+* Fixed missing sign-extensions that are required by the N32/N64 calling
+  convention when generating calls to library functions with 32-bit parameters.
+
+* ``-mno-odd-spreg`` is now honoured for vector insertion/extraction operations
+  when using ``-mmsa``.
+
+* Corrected the representation of member function pointers. This makes them
+  usable on microMIPS targets.
+
+* Fixed multiple segfaults and assertions in the disassembler when
+  disassembling instructions that have memory operands.
+
+* Fixed multiple cases of suboptimal code generation involving ``$zero`` and
+  redundant sign/zero extension.
+
+Non-comprehensive list of changes in 3.6.0
+==========================================
+
 .. NOTE
    For small 1-3 sentence descriptions, just add an entry at the end of
    this list. If your description won't fit comfortably in one bullet