[Polly][docs] Polly release notes.

Highlight work that has been done during the development window. After
cherry-picking D72372 to fix PR45001 no workaround is necessary anymore,
but the generalization of the linking mechanism is still worth pointing
out.

Author: Meinersbur

polly/docs/ReleaseNotes.rst

@@ -1,13 +1,16 @@
-=============================
-Release Notes 10.0 (upcoming)
-=============================
+==================
+Release Notes 10.0
+==================
 
 In Polly 10 the following important changes have been incorporated.
 
-.. warning::
+- The mechanism that Polly uses to link itself statically into the opt,
+  bugpoint and clang executables has been generalized such that it can
+  be used by other pass plugins. An example plugin "Bye" has been added
+  to LLVM to illustate the mechanism.
 
-  These releaes notes are for the next release of Polly and describe
-  the new features that have recently been committed to our development
-  branch.
-
-- Change ...
+- Some ScopInfo methods that are only relevant during SCoP construction
+  have been moved into the ScopBuilder class. In addition to making it
+  clearer which methods can only be used during the construction phase,
+  the refactoring helps shrinking the size of the public header
+  ScopInfo.h.