Bug 846018 - Add a pregion command to .gdbinit. r=BenWa

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extra : rebase_source : 000e708c5500aec55fb4ea6bbff37dede09e9807
Bug 1089008 - Enable e10s on Windows when acceleration is disabled. r=Mossop, r=felipe

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extra : rebase_source : f24efd7b76e111390de71d74ccace735dc9bbb88
Backed out changeset 047d21f101de (bug 846018)