Re-land [GreedyRA ORE] Add Cost of spill locations into remark

Re-land the patch with a fix of clang test.

Cost of spill location is computed basing on relative branch frequency
where corresponding spill/reload/copy are located.

While the number itself is highly depends on incoming IR,
the total cost can be used when do some changes in RA.

Revert "Revert "[GreedyRA ORE] Add Cost of spill locations into remark""
This reverts commit 680f3d6d.