[coco8] Issue report: Evaluating simple expression

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[coco8] Issue report: Evaluating simple expression

Summary: Execution of a JavaScript expression (produces a large amount of garbage), can result in an EXC_BAD_ACCESS.

Expected Results: The expression should evaluate an arbitrary number of times without issue.

Actual Results: Memory appears to be corrupted causing EXC_BAD_ACCESS.

Steps to reproduce:

Download the bug8 Xcode project (compressed file)
Open Bug/Bug.xcodeproj with Xcode 8.
Run the application on an iPhone 6s.
1. The expression in Bug/default.app.js is evaluated during application startup. This will cause the application to crash.

Notes:

The executed expression activates a Smalltalk to Javascript translator. The translated Smalltalk code is then evaluated within the JavaScripCore environment.
If a GC is forced (via the JSSynchronousGarbageCollectForDebugging function) the issue appears to subside. This can be tested by uncommenting the ‘print("gcNow “+gcNow.ms()+”ms");' line in mini8/default.app.js. This causes a full synchronous garbage collection to occur after each execution of the expression.

Configuration: Xcode 8.0 beta (8S128d), iPhone 6s iOS 9.3.2 (13F69)