Upgrade lz4 to v1.9.4 am: 996c91caedmain-16k-with-phones

Original change: https://android-review.googlesource.com/c/platform/external/lz4/+/2242764

Change-Id: I10ea4937eaf0cb6721ea50057ee861deaa157760
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/.github/workflows/README.md b/.github/workflows/README.md
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+This directory contains [GitHub Actions](https://github.com/features/actions) workflow files.
+
+# Known issues
+
+## USAN, ASAN (`lz4-ubsan-x64`, `lz4-ubsan-x86`, `lz4-asan-x64`)
+
+For now, `lz4-ubsan-*` ignores the exit code of `make usan` and `make usan32`.
+Because there are several issues which may take relatively long time to resolve.
+
+We'll fully enable it when we ensure `make usan` is ready for all commits and PRs.
+
+See [#983](https://github.com/lz4/lz4/pull/983) for details.
+
+
+## C Compilers (`lz4-c-compilers`)
+
+- Our test doesn't use `gcc-4.5` due to installation issue of its package.  (`apt-get install gcc-4.5` fails on GH-Actions VM)
+
+- Currently, the following 32bit executable tests fail with all versions of `clang`.
+  - `CC=clang-X CFLAGS='-O3' make V=1 -C tests clean test-lz4c32`
+  - `CC=clang-X CFLAGS='-O3 -mx32' make V=1 -C tests clean test-lz4c32`
+  - See [#991](https://github.com/lz4/lz4/issues/991) for details.
+
+- Currently, the following 32bit executable tests fail with `gcc-11`
+  - `CC=gcc-11 CFLAGS='-O3' make V=1 -C tests clean test-lz4c32`
+  - `CC=gcc-11 CFLAGS='-O3 -mx32' make V=1 -C tests clean test-lz4c32`
+  - See [#991](https://github.com/lz4/lz4/issues/991) for details.
+
+
+## cppcheck (`lz4-cppcheck`)
+
+This test script ignores the exit code of `make cppcheck`.
+Because this project doesn't 100% follow their recommendation.
+Also sometimes it reports false positives.
+
+
+
+# Notes
+
+- You can investigate various information at the right pane of GitHub
+  Actions report page.
+
+| Item                      | Section in the right pane             |
+| ------------------------- | ------------------------------------- |
+| OS, VM                    | Set up job                            |
+| git repo, commit hash     | Run actions/checkout@v2               |
+| Version of tools          | Environment info                      |
+
+
+
+# Difference with `.travis.yml`
+
+The following tests are not included yet.
+
+- name: Compile OSS-Fuzz targets
+
+The following tests will not be included due to limitation of GH-Actions.
+
+- name: aarch64 real-hw tests
+- name: PPC64LE real-hw tests
+- name: IBM s390x real-hw tests