CHROMIUM: Add #line to stack.c

Work around coreboot GCC preprocessor bug.

BUG=b:272518464
TEST=BOARD=orisa ; zmake build -c $BOARD &&
./util/find_non_exec_lines.py build/zephyr/$BOARD/output/zephyr.info

Change-Id: Ib80caa8ece3bfc86810c615a0361680f393e7c58
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5836175
Commit-Queue: Jeremy Bettis <jbettis@chromium.org>
Reviewed-by: Tomasz Michalec <tmichalec@google.com>
Commit-Queue: ChromeOS Auto Runner <chromeos-auto-runner@chromeos-bot.iam.gserviceaccount.com>
Tested-by: Jeremy Bettis <jbettis@chromium.org>

kernel/stack.c

@@ -4,6 +4,12 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/*
+ * TODO(b/272518464): Work around coreboot GCC preprocessor bug.
+ * #line marks the *next* line, so it is off by one.
+ */
+#line 12
+
 /**
  * @brief fixed-size stack object
  */