Merge pull request #314 from leeN/debug_mode

First step towards a useful debug mode

Update number of tools

Overlay existing taint for custom sources (#258)

* Fixes #257 to prevent losing taint information for already tainted strings
* Bugfix StringTaint -> SafeStringTaint to prevent memory leaks

Fixing String conversion bug (#249)

* Fixed taint propagation for String conversion fast path and utf8 strings
* Added integration tests

Foxhound: remove unnecessary bailout for StringTrim operations

Foxhound: fixing memory leaks and crashses

The fix to clean up all the StringTaint from Nursery strings
wasn't quite thorough enough and left some dangling pointers
lying around. This fix makes sure we catch all the Nursery
allocated Strings by moving String registration to Allocator-inl.h

This fix revealed the root cause of the segmentation faults which
were occuring on client-heavy webapps (UI5 I'm looking at you).
There were a couple of occasions where strings were being created
(but not rooted) and then additional strings constructed for
TaintOperation arguments (e.g. JSONParser.cpp and RegExp.cpp).
As the TaintOperations were trying to allocate memory, this
could cause a GC which would clean up the original strings.

This fix makes sure that the TaintOperations are created before
the new Strings or that they are properly rooted.

Foxhound: tainting StringBuffer before String creation

Merge branch 'dev-xhr-header'

Merge branch 'playwright-1.39.0' into main

Updating to playwright 1.39 patches

Adding Mochitests for Taint Propagation