Cross-reference from release notes to supported platforms.

Copied from Perforce
 Change: 193827

mps/manual/source/code-index.rst

@@ -349,7 +349,7 @@ expt825.c         Regression test for job000825_.
 fbmtest.c         Free block manager (CBS and Freelist) test.
 finalcv.c         :ref:`topic-finalization` coverage test.
 finaltest.c       :ref:`topic-finalization` test.
-forktest.c        :ref:`topic-fork-safety` test.
+forktest.c        :ref:`topic-thread-fork` test.
 fotest.c          Failover allocator test.
 landtest.c        Land test.
 locbwcss.c        Locus backwards compatibility stress test.

mps/manual/source/guide/overview.rst

@@ -43,6 +43,8 @@ for details.
    single: Memory Pool System; supported target platforms
    single: platforms; supported
 
+.. _guide-overview-platforms:
+
 Supported target platforms
 --------------------------
 

mps/manual/source/release.rst

@@ -33,7 +33,8 @@ New features
 #. The MPS no longer supports Linux 2.4 and 2.5. (These versions used
    LinuxThreads_ instead of POSIX threads; all major distributions
    have long since ceased to support these versions and so it is no
-   longer convenient to test against them.)
+   longer convenient to test against them.) See
+   :ref:`guide-overview-platforms`.
 
    .. _LinuxThreads: http://pauillac.inria.fr/~xleroy/linuxthreads/