fuzz: add helper scripts

test/fuzz/build-libfuzzer.sh

+#!/bin/bash
+SCRIPT_DIR="$(cd "$(dirname $0)" && pwd)"
+BUILD_DIR=/tmp
+LIBFUZZER_SRC=$BUILD_DIR/Fuzzer
+
+get_libfuzzer() {
+    git clone https://chromium.googlesource.com/chromium/llvm-project/llvm/lib/Fuzzer $LIBFUZZER_SRC ||
+    (cd $LIBFUZZER_SRC && git pull)
+}
+
+get_libfuzzer &&
+cd $LIBFUZZER_SRC && ./build.sh &&
+cp $LIBFUZZER_SRC/libFuzzer.a $SCRIPT_DIR/

test/fuzz/run-fuzzer.sh

+jobs=1
+
+./libvlc_demux_fuzzer -jobs=$jobs DEMUX_CORPUS/AVI
+./libvlc_demux_fuzzer -jobs=$jobs DEMUX_CORPUS/FLV
+./libvlc_demux_fuzzer -jobs=$jobs DEMUX_CORPUS/MKV
+./libvlc_demux_fuzzer -jobs=$jobs DEMUX_CORPUS/MP4 -dict=dictionaries/mp4.dict
+./libvlc_demux_fuzzer -jobs=$jobs DEMUX_CORPUS/MPEG1
+./libvlc_demux_fuzzer -jobs=$jobs DEMUX_CORPUS/MPEG2
+./libvlc_demux_fuzzer -jobs=$jobs DEMUX_CORPUS/OPUS
+
+./libvlc_decoder_fuzzer -jobs=$jobs --codec=H264 DECODER_CORPUS/H264
+./libvlc_decoder_fuzzer -jobs=$jobs --codec=H265 DECODER_CORPUS/H265
+./libvlc_decoder_fuzzer -jobs=$jobs --codec=MP2V DECODER_CORPUS/MP2V
+./libvlc_decoder_fuzzer -jobs=$jobs --codec=MP4V DECODER_CORPUS/MP4V
+./libvlc_decoder_fuzzer -jobs=$jobs --codec=VC-1 DECODER_CORPUS/VC-1