Import Cobalt 19.master.0.203780

Includes the following patches:
  https://cobalt-review.googlesource.com/c/cobalt/+/5210
    by errong.leng@samsung.com
  https://cobalt-review.googlesource.com/c/cobalt/+/5270
    by linus.wang@samsung.com
diff --git a/src/third_party/llvm-project/clang-tools-extra/docs/clang-tidy/checks/cert-err09-cpp.rst b/src/third_party/llvm-project/clang-tools-extra/docs/clang-tidy/checks/cert-err09-cpp.rst
new file mode 100644
index 0000000..1494bcc
--- /dev/null
+++ b/src/third_party/llvm-project/clang-tools-extra/docs/clang-tidy/checks/cert-err09-cpp.rst
@@ -0,0 +1,10 @@
+.. title:: clang-tidy - cert-err09-cpp
+.. meta::
+   :http-equiv=refresh: 5;URL=misc-throw-by-value-catch-by-reference.html
+
+cert-err09-cpp
+==============
+
+The cert-err09-cpp check is an alias, please see
+`misc-throw-by-value-catch-by-reference <misc-throw-by-value-catch-by-reference.html>`_
+for more information.