C API: Add LLVMCloneModule()

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218775 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Call EmitFunctionHeader() in the AsmPrinter to populate the ELF symbol table

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218776 91177308-0d34-0410-b5e6-96231b3b80d8