This patch follows is a follow up to r178171, which uses the register

form of call in preference to memory indirect on Atom.

In this case, the patch applies the optimization to the code for reloading
spilled registers.

The patch also includes changes to sibcall.ll and movgs.ll, which were
failing on the Atom buildbot after the first patch was applied.

This patch by Sriram Murali.

llvm-svn: 178193