solve the pcre stack overflow #1576 - was: stack vs workspace for pcre and others

[Nils Goroll]

> "which part of recursive didn't you understand ?"

pcre allows to limit the recursion depth. iirc, the original plan was to
determine the available space and calculate a safe upper bound for the recursion
depth.

The remaining issue with JIT, besides bugs, is that the 32k jit stack
allocatited from the machine stack may not suffice. See CONTROLLING THE JIT
STACK in pcrejit(3)