Fix signal test to work with gcstress

We now avoid running GC if we are handling a stack overflow, this
helps prevent running past the end of the stack overflow reserved
bytes.

Added logic in ThrowStackOverflowError to use a stack overflow
exception without a stack trace if we fail to allocate the stack
trace.

Bug: 16406852
Change-Id: Ib34e235cd0af6d7c4c93c9705fa822f2b9b23b38
5 files changed