Treat WASM_FUNCTION frames as stubs.

Treat WASM_FUNCTION frames as stubs.

This is "more correct" than WASM_FUNCTION falling through the switch
over code types and using the marker on the stack which contains a bogus
value.

In the long run, there will be two kinds of WASM-related frames: frames
that cross the JS/WASM border, and internal WASM_FUNCTION frames. This
will necessitate a new StackFrame::Type, since the first kind of frame
must treat its parameters as tagged values and the second definitely
should not.

R=mstarzinger@chromium.org
BUG=

Committed: https://crrev.com/2c37146bfaeafcacaf549a013fa9ab0519db3bf9
Cr-Commit-Position: refs/heads/master@{#32256}

[Michael Starzinger, 2015-11-25 09:22:39]

LGTM if the stack-walks still work for you.

[titzer, 2015-11-25 09:32:00]

The CQ bit was checked by titzer@chromium.org

[commit-bot: I haz the power, 2015-11-25 09:32:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1470353002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1470353002/1

[commit-bot: I haz the power, 2015-11-25 09:33:32]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-25 09:33:46]

Patchset 1 (id:??) landed as
https://crrev.com/2c37146bfaeafcacaf549a013fa9ab0519db3bf9
Cr-Commit-Position: refs/heads/master@{#32256}