Revert "Support "preserving" the summary information when using setModule()...

Revert "Support "preserving" the summary information when using setModule() API in LTOCodeGenerator"

This reverts commit r267657, r267656, and r267655.
The test does not pass on multiple bots, I'm unsure why yet but let's unbreak them.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267664