This stuff is fairly isolated in terms of what it touches and I'm sure
if anything goes wrong, Aldy, Richard& Torvald will be available to
fix it.
The request to merge came in before the end of stage1, I don't see a
reason to delay things another 6-9 months. This isn't like asking to
pull in a whole new register allocator at the end of stage1 :-)
Additionally, I believe we have a small window where we can position
GCC to be the compiler of choice for those working with TM; waiting
6-9 months for GCC 4.8 will miss that window.