Split out fallback stack limit determination.
In case we're unable to get an estimate of the stack size for a platform
thread, a small stack size is assumed and its effective upper bound is
then probed and computed.
Do that in a separate method to avoid compiler-injected stack exhaustion checks
(MSVC's _chkstk()) from being always run for StackFrameDepth::enableStackLimit().
This also facilitates running GCs when up against stack pressure on Windows
platforms.
R=haraken
BUG=582819
Review URL: https://codereview.chromium.org/1673543002
Cr-Commit-Position: refs/heads/master@{#373787}
2 files changed
