Remove deprecated llvm.experimental.gc.result.{int,float,ptr} intrinsics.

Summary:
These were deprecated 11 months ago when a generic
llvm.experimental.gc.result intrinsic, which works for all types, was added.

Reviewers: sanjoy, reames

Subscribers: sanjoy, chenli, llvm-commits

Differential Revision: http://reviews.llvm.org/D15719

llvm-svn: 256262