Bump the trunk version to 4.0.0svn.

Differential Revision: https://reviews.llvm.org/D21821

llvm-svn: 275827
diff --git a/llvm/docs/DeveloperPolicy.rst b/llvm/docs/DeveloperPolicy.rst
index 23bdb2f..b6555b0 100644
--- a/llvm/docs/DeveloperPolicy.rst
+++ b/llvm/docs/DeveloperPolicy.rst
@@ -510,8 +510,7 @@
 * Additions and changes to the IR should be reflected in
   ``test/Bitcode/compatibility.ll``.
 
-* The bitcode format produced by a X.Y release will be readable by all
-  following X.Z releases and the (X+1).0 release.
+* The current LLVM version supports loading any bitcode since version 3.0.
 
 * After each X.Y release, ``compatibility.ll`` must be copied to
   ``compatibility-X.Y.ll``. The corresponding bitcode file should be assembled
diff --git a/llvm/docs/conf.py b/llvm/docs/conf.py
index 224cca1..d7e9e2d 100644
--- a/llvm/docs/conf.py
+++ b/llvm/docs/conf.py
@@ -48,9 +48,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = '3.9'
+version = '4.0'
 # The full version, including alpha/beta/rc tags.
-release = '3.9'
+release = '4.0'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.