Oss-fuzz ideal integration (unicorn-engine#1265)

* Adds oss-fuzz badge

* Generic fix for watchpoints leak

Author: catenacyber

README.md

@@ -4,6 +4,7 @@ Unicorn Engine
 [![Join the chat at https://gitter.im/unicorn-engine/chat](https://badges.gitter.im/unicorn-engine/unicorn.svg)](https://gitter.im/unicorn-engine/chat?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![Build Status](https://travis-ci.org/unicorn-engine/unicorn.svg?branch=master)](https://travis-ci.org/unicorn-engine/unicorn)
 [![pypi downloads](https://pepy.tech/badge/unicorn)](https://pepy.tech/project/unicorn)
+[![Fuzzing Status](https://oss-fuzz-build-logs.storage.googleapis.com/badges/unicorn.svg)](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:unicorn)
 
 Unicorn is a lightweight, multi-platform, multi-architecture CPU emulator framework
 based on [QEMU](http://qemu.org).

qemu/target-arm/unicorn_arm.c

@@ -32,7 +32,6 @@ void arm_release(void* ctx)
     g_free(cpu->cpreg_values);
     g_free(cpu->cpreg_vmstate_indexes);
     g_free(cpu->cpreg_vmstate_values);
-    cpu_watchpoint_remove_all(CPU(cpu), BP_CPU);
 
     release_common(ctx);
 }

qemu/unicorn_common.h

@@ -51,6 +51,7 @@ static void release_common(void *t)
     memory_free(s->uc);
     tb_cleanup(s->uc);
     free_code_gen_buffer(s->uc);
+    cpu_watchpoint_remove_all(CPU(s->uc->cpu), BP_CPU);
 
 #if TCG_TARGET_REG_BITS == 32
     for(i = 0; i < s->nb_globals; i++) {