[Remarks] Extend -fsave-optimization-record to specify the format

Use -fsave-optimization-record=<format> to specify a different format
than the default, which is YAML.

For now, only YAML is supported.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@363573 91177308-0d34-0410-b5e6-96231b3b80d8
14 files changed