fuzz: adds support for minimization via wasm-tools shrink (#1844)

Signed-off-by: Takeshi Yoneda <t.y.mathetake@gmail.com>

internal/integration_test/fuzz/README.md

@@ -80,6 +80,16 @@ Minimize test case with:
 and you can use that command to "minimize" the input binary while keeping the same error.
 
 
+Alternatively, you can use the following command to minimize the arbitrary input binary:
+
+```
+go test -c ./wazerolib -o nodiff.test && wasm-tools shrink ./predicate.sh original.{wasm,wat} -o shrinken.wasm --attempts 4294967295
+```
+
+which uses `wasm-tools shrinken` command to minimize the input binary. Internally, the `predicate.sh` is invoked for each input binary
+where it executes the `nodiff.test` binary which runs `TestReRunFailedRequireNoDiffCase`.
+
+
 ### Run fuzzing on wazevo
 
 Until we replace the existing compiler with the new optimizing compiler `wazevo`,

internal/integration_test/fuzz/predicate.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+# The Wasm file is given as the first and only argument to the script.
+WASM=$1
+
+echo "Testing $WASM"
+
+export WASM_BINARY_PATH=$WASM
+
+# Run the test and reverse the exit code so that a non-zero exit code indicates interesting case.
+./nodiff.test
+exit $((! $?))