Add missing space.

llvm-svn: 183386
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 501a2a6..5808e0e 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -85,7 +85,7 @@
 --------------
 
 Removed support for legacy hexagonv2 and hexagonv3 processor architectures which
-are no longer in use. Currently supported architectures arehexagonv4 and
+are no longer in use. Currently supported architectures are hexagonv4 and
 hexagonv5.
 
 Mips target