This tracks TlsAlloc() and TlsFree() calls on Windows for diagnosing crashes when a proces reaches
its limit (1088) for TLS slots. Tracking of TLS allocation is done by intercepting TlsAlloc() and
TlsFree() in kernel32.dll. After initialization, we start tracking the number of allocated TLS
slots. If the number of observed TLS allocations exceeds a high water mark, we record the stack
when TlsAlloc() is called, and the recorded stacks gets serialized in a JSON string ready for
crash annotation.
MozReview-Commit-ID: 5fHVr0eiMy5