@petermarshall, bisect points to your change, please investigate.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5531804401664000

Fuzzer: mbarbella_js_mutation
Job Type: linux_asan_d8_v8_mipsel_dbg
Platform Id: linux

Crash Type: CHECK failure
Crash Address: 
Crash State:
  !v8::internal::FLAG_enable_slow_asserts || (object->IsHeapObject()) in objects-i
  
Sanitizer: address (ASAN)

Regressed: V8: r42454:42455

Minimized Testcase (0.25 Kb):
Download: https://cluster-fuzz.appspot.com/download/AMIfv97HvwbIauSObJ1Fntpm1hQxEYyR8CyiKTOQRlLPJ7-S4Rnay1STAC5y1Oeo5Hbms8UTvrXgIqLEqrR29KRdfhlGcj8pduI9zn4I6Tnt5RCF9n0Ys9juXZDhFrs70FEmFSwJtUpGlMQer5OwoXLoZDFAaFKTsI92a--DmEO29Uj1Lgpww_9EGJJvCIx6VhqqboqwDwZ1t8hNEmxb6WxpNljxVDBcyHpyYoj11yh5XqQkucmwyPtK6qSk1bTsiZzlPYOvb9QZ-hhvO8hCkwDy4GsywumqCTkcbOySBNNP4VjmwgYA9o7vVbUmQQW98EtNbx6Zs94OHPov6rJc_pB4gO68z5wLPVW7KzYtBW47aXcMBpshWZE?testcase_id=5531804401664000
try {
} catch(e) {; }
function __f_0() {
}
try {
(function __f_1() {
})();
} catch(e) {; }
(function __f_5() {
  function __f_7(a, b) {
    this.args = [ b, c];
  }
new __f_7(...[4294967295, 1073741823]), __f_7;
})();
__v_9 = {
  toString: function() {
  },
};


See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs for more information.

ClusterFuzz has detected this issue as fixed in range 42469:42470.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5531804401664000

Fuzzer: mbarbella_js_mutation
Job Type: linux_asan_d8_v8_mipsel_dbg
Platform Id: linux

Crash Type: CHECK failure
Crash Address: 
Crash State:
  !v8::internal::FLAG_enable_slow_asserts || (object->IsHeapObject()) in objects-i
  
Sanitizer: address (ASAN)

Regressed: V8: 42454:42455
Fixed: V8: 42469:42470

Minimized Testcase (0.25 Kb):
Download: https://cluster-fuzz.appspot.com/download/AMIfv97HvwbIauSObJ1Fntpm1hQxEYyR8CyiKTOQRlLPJ7-S4Rnay1STAC5y1Oeo5Hbms8UTvrXgIqLEqrR29KRdfhlGcj8pduI9zn4I6Tnt5RCF9n0Ys9juXZDhFrs70FEmFSwJtUpGlMQer5OwoXLoZDFAaFKTsI92a--DmEO29Uj1Lgpww_9EGJJvCIx6VhqqboqwDwZ1t8hNEmxb6WxpNljxVDBcyHpyYoj11yh5XqQkucmwyPtK6qSk1bTsiZzlPYOvb9QZ-hhvO8hCkwDy4GsywumqCTkcbOySBNNP4VjmwgYA9o7vVbUmQQW98EtNbx6Zs94OHPov6rJc_pB4gO68z5wLPVW7KzYtBW47aXcMBpshWZE?testcase_id=5531804401664000
try {
} catch(e) {; }
function __f_0() {
}
try {
(function __f_1() {
})();
} catch(e) {; }
(function __f_5() {
  function __f_7(a, b) {
    this.args = [ b, c];
  }
new __f_7(...[4294967295, 1073741823]), __f_7;
})();
__v_9 = {
  toString: function() {
  },
};


See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz has detected this issue as fixed in range 42469:42470.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=6454755292610560

Fuzzer: mbarbella_js_mutation
Job Type: linux_asan_d8_ignition_dbg
Platform Id: linux

Crash Type: CHECK failure
Crash Address: 
Crash State:
  TailCallMode::kDisallow == expr->tail_call_mode() in bytecode-generator.cc
  
Sanitizer: address (ASAN)

Regressed: V8: 42454:42455
Fixed: V8: 42469:42470

Minimized Testcase (0.19 Kb):
Download: https://cluster-fuzz.appspot.com/download/AMIfv97A63qB0MV6wONU0bz-dQXb360USBvLwp9kDpFZjqhyuaNj6ZbayC7sLUOJdNrV0RNMA1nmT6KaRid1SL01sgW30tJJzDZ-txNCeRjzuqsfeE1Q4rB2opGhHKVWspneb8cMrDiz-q60i7tZmQQEZhRWjRsdV3f5Qx48WzpEaBBwVlmz2t5xQkhl1MkkLSZI7QDfirPRhX-b3x97-cjJ6Moct8-hp8n-JMDA39mWIPZls8ExHq-eU_xJagL0IjRtRpKHx7SE_OldJp4HalRcyoF6iMSf9SV5mFS_f-UQMPz2vbwf-Vt_t7dERYeTDdKACim0kxQwFYNGuV9ykkPFZwthLi2P7nT99s9I8z5_peu0Gt-k_M8?testcase_id=6454755292610560
__v_8 = (function () {
})();
  class BaseClass {
  }
  class SubClass extends BaseClass {
    method() { return super.method(...args); }
  }
  var __v_8 = new SubClass();
[], __v_8.method();


See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase 5531804401664000 is verified as fixed, so closing issue.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.