Bug 908001: Reuse default block for non cases in giant sparse switch tables in Odin; r=mjrosenb
Backed out changeset 3a1f27080f9c (bug 906811) for Linux mochitest failures.
Backed out 2 changesets (bug 909447, bug 909441) for jit-test failures on a CLOSED TREE.

Backed out changeset 3300c750cd53 (bug 909447)
Backed out changeset b1b242a80ef7 (bug 909441)
Backed out changeset 70153e30c826 (bug 823822) for bringing back the crashtest failures it was supposed to be fixing.
CLOSED TREE