Spill registers before scanning the stack.

From the change:

    // xtensa has more registers than an instruction can address. The 16 that
    // can be addressed are called the "window". When a function is called or
    // returns the window rotates. This allows for more efficient function calls
    // because ram doesn't need to be used. It's only used if the window wraps
    // around onto itself. At that point values are "spilled" to empty spots in
    // the stack that were set aside. When the window rotates back around (on
    // function return), the values are restored into the register from ram.

    // So, in order to read the values in the stack scan we must make sure all
    // of the register values we care about have been spilled to RAM. Luckily,
    // there is a HAL call to do it. There is a bit of a race condition here
    // because the register value could change after it's been restored but that
    // is unlikely to happen with a heap pointer while we do a GC.

Fixes #2907

0 files changed, 0 insertions, 0 deletions