Beginning with r187629, stress/tail-call-no-stack-overflow.js fails when run on ARM64. Given that r187590 broke the branch, the regression could be in r187590, r187616 or r187618. Here is the relevant output from the test log: Running stress/tail-call-no-stack-overflow.js.default stress/tail-call-no-stack-overflow.js.default: Exception: RangeError: Maximum call stack size exceeded. stress/tail-call-no-stack-overflow.js.default: global code@tail-call-no-stack-overflow.js:37:21 stress/tail-call-no-stack-overflow.js.default: ERROR: Unexpected exit code: 3 FAIL: stress/tail-call-no-stack-overflow.js.default Running stress/tail-call-no-stack-overflow.js.always-trigger-copy-phase stress/tail-call-no-stack-overflow.js.always-trigger-copy-phase: Exception: RangeError: Maximum call stack size exceeded. stress/tail-call-no-stack-overflow.js.always-trigger-copy-phase: global code@tail-call-no-stack-overflow.js:37:21 stress/tail-call-no-stack-overflow.js.always-trigger-copy-phase: ERROR: Unexpected exit code: 3 FAIL: stress/tail-call-no-stack-overflow.js.always-trigger-copy-phase Running stress/tail-call-no-stack-overflow.js.no-llint stress/tail-call-no-stack-overflow.js.no-llint: Exception: RangeError: Maximum call stack size exceeded. stress/tail-call-no-stack-overflow.js.no-llint: global code@tail-call-no-stack-overflow.js:37:21 stress/tail-call-no-stack-overflow.js.no-llint: ERROR: Unexpected exit code: 3 FAIL: stress/tail-call-no-stack-overflow.js.no-llint Running stress/tail-call-no-stack-overflow.js.no-cjit-validate-phases stress/tail-call-no-stack-overflow.js.no-cjit-validate-phases: Exception: RangeError: Maximum call stack size exceeded. stress/tail-call-no-stack-overflow.js.no-cjit-validate-phases: global code@tail-call-no-stack-overflow.js:37:21 stress/tail-call-no-stack-overflow.js.no-cjit-validate-phases: ERROR: Unexpected exit code: 3 FAIL: stress/tail-call-no-stack-overflow.js.no-cjit-validate-phases Running stress/tail-call-no-stack-overflow.js.dfg-eager stress/tail-call-no-stack-overflow.js.dfg-eager: Exception: RangeError: Maximum call stack size exceeded. stress/tail-call-no-stack-overflow.js.dfg-eager: global code@tail-call-no-stack-overflow.js:37:21 stress/tail-call-no-stack-overflow.js.dfg-eager: ERROR: Unexpected exit code: 3 FAIL: stress/tail-call-no-stack-overflow.js.dfg-eager Running stress/tail-call-no-stack-overflow.js.dfg-eager-no-cjit-validate stress/tail-call-no-stack-overflow.js.dfg-eager-no-cjit-validate: Exception: RangeError: Maximum call stack size exceeded. stress/tail-call-no-stack-overflow.js.dfg-eager-no-cjit-validate: global code@tail-call-no-stack-overflow.js:37:21 stress/tail-call-no-stack-overflow.js.dfg-eager-no-cjit-validate: ERROR: Unexpected exit code: 3 FAIL: stress/tail-call-no-stack-overflow.js.dfg-eager-no-cjit-validate