This patch makes several fundamental changes to the logic we use to inform
the main process whenever the WER runtime exception module intercepts a child
process crash:
* We no longer read the process type or any other data from the child process;
the process type is passed as the runtime exception module's context
* We no longer read the address of the memory area used to communicate with the
main process from the child process arguments. Instead we allocate memory
directly into the main process and store the required information there
* We don't read anything from the main process either, the pointer to the
function used to notify the main process is now found by looking out its
dedicated section in the parent process' xul.dll mapping
* We no longer read the OOM crash annotation from a child process, this
functionality will be restored by making the module use the mozannotation
crates to fetch all the annotations
Differential Revision: https://phabricator.services.mozilla.com/D201589
