[wasm] Update and run script to generate fuzzer corpus

The wasm fuzzer corpus is pretty outdated. The script that was used to
generate it did not work any more.
This CL updates the script, and runs it. This generates a fuzzer corpus
of 42011 wasm modules, compared to 15290 before. The new modules will
contain new features like SIMD and multi-value, which will be
interesting fuzzer inputs.

R=ahaas@chromium.org

Change-Id: Ic3df26930cb8c1c6e8d521597ceb06cc338c02ed
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2565512Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71537}

test/fuzzer/wasm_corpus.tar.gz.sha1

-f6b95b7dd8300efa84b6382f16cfcae4ec9fa108
\ No newline at end of file
+a1493bb387aed38462c49f4351dc47e79e4b784b
\ No newline at end of file

tools/wasm/update-wasm-fuzzers.sh

@@ -3,40 +3,29 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-set -e
+set -ex
 
-TOOLS_WASM_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+cd "$( dirname "${BASH_SOURCE[0]}" )"
+cd ../..
 
-cd ${TOOLS_WASM_DIR}/../..
+BUILD_DIR=out/mk_wasm_fuzzer_corpus
+CORPUS_DIR=test/fuzzer/wasm_corpus
 
-rm -rf test/fuzzer/wasm_corpus
+rm -rf $BUILD_DIR $CORPUS_DIR
+mkdir -p $CORPUS_DIR
 
-tools/dev/gm.py x64.release all
+# Build optdebug such that the --dump-wasm-module flag is available.
+gn gen $BUILD_DIR --args='is_debug=true v8_optimized_debug=true target_cpu="x64" use_goma=true'
+autoninja -C $BUILD_DIR
 
-mkdir -p test/fuzzer/wasm_corpus
+./tools/run-tests.py --outdir=$BUILD_DIR --extra-flags="--dump-wasm-module \
+  --dump-wasm-module-path=./$CORPUS_DIR/"
 
-# wasm
-./tools/run-tests.py -j8 --variants=default --timeout=10 --arch=x64 \
-  --mode=release --no-presubmit --extra-flags="--dump-wasm-module \
-  --dump-wasm-module-path=./test/fuzzer/wasm_corpus/" unittests
-./tools/run-tests.py -j8 --variants=default --timeout=10 --arch=x64 \
-  --mode=release --no-presubmit --extra-flags="--dump-wasm-module \
-  --dump-wasm-module-path=./test/fuzzer/wasm_corpus/" wasm-spec-tests/*
-./tools/run-tests.py -j8 --variants=default --timeout=10 --arch=x64 \
-  --mode=release --no-presubmit --extra-flags="--dump-wasm-module \
-  --dump-wasm-module-path=./test/fuzzer/wasm_corpus/" mjsunit/wasm/*
-./tools/run-tests.py -j8 --variants=default --timeout=10 --arch=x64 \
-  --mode=release --no-presubmit --extra-flags="--dump-wasm-module \
-  --dump-wasm-module-path=./test/fuzzer/wasm_corpus/" \
-  $(cd test/; ls cctest/wasm/test-*.cc | \
-  sed -es/wasm\\///g | sed -es/[.]cc/\\/\\*/g)
+rm -rf $BUILD_DIR
 
 # Delete items over 20k.
-for x in $(find ./test/fuzzer/wasm_corpus/ -type f -size +20k)
-do
-  rm $x
-done
+find $CORPUS_DIR -type f -size +20k | xargs rm
 
 # Upload changes.
-cd test/fuzzer
+cd $CORPUS_DIR/..
 upload_to_google_storage.py -a -b v8-wasm-fuzzer wasm_corpus