Get us closer to use release build config

To make releases look more like Releases:

https://gitweb.torproject.org/tor-browser.git/tree/build/unix/mozconfig.linux32?h=tor-browser-60.5.1esr-8.5-1

legacy/trac#23656 (moved) Use .mozconfig files in tor-browser repo for rbm builds

+ac_add_options --enable-debug-symbols=""

+export BUILDING_RELEASE=1 (https://gitweb.torproject.org/tor-browser.git/tree/browser/config/mozconfigs/linux64/release?h=tor-browser-60.5.1esr-8.5-1)

-mk_add_options BUILD_OFFICIAL=1

-mk_add_options MOZILLA_OFFICIAL=1

-ac_add_options --enable-default-toolkit=cairo-windows

legacy/trac#29081 (moved) libwinpthread.dll has no ASLR

-O2 (-O3 for js) for mingw

-no-seh for win32