[PATCH] Move calls to llvm.gcroot() when inlining.

[Ben Karel]

  Two quick notes:

  1) I disabled lifetime markers for allocas that flow to gcroot() because I assume the gcroot call would get removed for existing outside the lifetime-marker-induced live range.

  2) Because we insert at the end of the entry block, there may be non-adjacent "blocks" of calls to gcroot(). I don't think that's a problem, but I thought it might be worth pointing out.

http://llvm-reviews.chandlerc.com/D1935