release_notes: 5.17 is out, add tentative 5.18 section

So far, the main accepted 5.18 patches are just the
assertion/expectation rewrite ones.

Stubbing and resource API changes are big, but haven't been merged into
any tree yet. Will update if they make it into 5.18.

Change-Id: I999df7c6cb259c13dff22b7bfda7d982ca7237d1
Signed-off-by: Daniel Latypov <dlatypov@google.com>
diff --git a/release_notes.rst b/release_notes.rst
index 58dfd54..9796c38 100644
--- a/release_notes.rst
+++ b/release_notes.rst
@@ -160,8 +160,8 @@
 
 - In-kernel documentation has been significantly revamped.
 
-5.17 (tentative)
-================
+5.17
+====
 
 - Print out parsed test results in real time.
 
@@ -191,3 +191,13 @@
 	[12:37:14] ================= [PASSED] ext4_inode_test =================
 	[12:37:14] ============================================================
 
+
+5.18 (tentative)
+================
+
+- Drastically decrease stack usage of ``KUNIT_EXPECT_`` macros.
+
+  - Before, we largely relied on the compiler to optimize away some internal
+    structs, but that didn't always work.
+
+  - Now on UML (x86_64), ``KUNIT_EXPECT_EQ()`` uses 32 bytes instead of 88.