[Doc] Add doc about creduce options to disable rename passes

Those Creduce options are from https://github.com/llvm/llvm-project/pull/89807#issuecomment-2102760018.
5adfcb0750
makes it possible to pass Creduce options directly to creduce-clang-crash.py

Change-Id: I09bbd4f5cda677fb6fa1b591b56d2b4256f6b187
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5538755
Auto-Submit: Zequan Wu <zequanwu@google.com>
Commit-Queue: Zequan Wu <zequanwu@google.com>
Reviewed-by: Amy Huang <akhuang@google.com>
Cr-Commit-Position: refs/heads/main@{#1301490}

docs/clang_gardening.md

@@ -140,7 +140,13 @@ things:
        clang/utils/creduce-clang-crash.py --llvm-bin bin \
            angle_deqp_gtest-d421b0.sh angle_deqp_gtest-d421b0.cpp
 
-   Attach the reproducer to the llvm bug you filed in the previous step.
+   Attach the reproducer to the llvm bug you filed in the previous step. You can
+   disable Creduce's renaming passes with the options
+   `--remove-pass pass_clang rename-fun --remove-pass pass_clang rename-param
+   --remove-pass pass_clang rename-var --remove-pass pass_clang rename-class
+   --remove-pass pass_clang rename-cxx-method --remove-pass pass_clex
+   rename-toks` which makes it easier for the author to reason about and to
+   further reduce it manually.
 
    If you need to do something the wrapper doesn't support,
    follow the [official CReduce docs](https://embed.cs.utah.edu/creduce/using/)