Do not create a replaceable Variables MDNode for function forward decls.

These fields would need to be explicitly deleted before we RAUW the temporary
node anyway (this was done in cfe commit r222373). Instead, do not create
these useless nodes in the first place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222434 91177308-0d34-0410-b5e6-96231b3b80d8
Add missing copyright headers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222435 91177308-0d34-0410-b5e6-96231b3b80d8
Make DWARFAcceleratorTable::dump() const.

As dump() methods  should be. To allow that, do not store the DWARFFormValue
objects used for the dump in the header data.

Per Alexey's suggestion!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222436 91177308-0d34-0410-b5e6-96231b3b80d8