[ICP] Migrate to OptimizationRemarkEmitter

This is a module pass so for the old PM, we can't use ORE, the function
analysis pass.  Instead ORE is created on the fly.

A few notes:

- isPromotionLegal is folded in the caller since we want to emit the Function
in the remark but we can only do that if the symbol table look-up succeeded.

- There was good test coverage for remarks in this pass.

- promoteIndirectCall uses ORE conditionally since it's also used from
SampleProfile which does not use ORE yet.

Fixes PR33792.

Differential Revision: https://reviews.llvm.org/D35929

llvm-svn: 309294