If a metadata operand is seeded in value map and the metadata should also be seeded...

If a metadata operand is seeded in value map and the metadata should also be seeded in value map. This is not limited to function local metadata.

Failure to seed metdata in such cases causes troubles when in a cloned module, metadata from a new module refers to values in old module. Usually this results in mysterious bugpoint crashes. For example,

 Checking to see if we can delete global inits: Unknown constant!
 UNREACHABLE executed at /d/g/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp:904!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106592 91177308-0d34-0410-b5e6-96231b3b80d8