Revert r329403 "[llvm-mca] Do not separate iterations with a newline in the timeline view."

This made AArch64/CortexA57/direct-branch.s fail on Windows, e.g.
http://lab.llvm.org:8011/builders/clang-x86-windows-msvc2015/builds/11251

> Also, update a few tests to minimize the diff in D45369.
> No functional change intended.

llvm-svn: 329569