[PlaceSafepoints] Assertion on that gc_result can not have preceding phis...

[PlaceSafepoints] Assertion on that gc_result can not have preceding phis should only apply to invoke statepoint

Summary: When PlaceSafepoints pass replaces old return result with gc_result from statepoint, it asserts that gc_result can not have preceding phis in its parent block. This is only true on invoke statepoint, which terminates the block and puts its result at the beginning of the normal successor block. Call statepoint does not terminate the block and thus its result is in the same block with it. There should be no restriction on whether there are phis or not.

Reviewers: reames, igor-laevsky

Reviewed By: igor-laevsky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9803

llvm-svn: 237597