When emit-obj from clang directly, DirectX backend will hit assert caused by not initialize passes for AsmPrinter.
The fix will initialize the passes by calling createPassConfig.
Also ignore global variable which not has section in DXILAsmPrinter::emitGlobalVariable to avoid hit llvm_unreachable in DXILTargetObjectFile::SelectSectionForGlobal.
Reviewed By: beanz
Differential Revision: https://reviews.llvm.org/D130856
The DXILAsmPrinter will just write globals into sections, so the
DXILAsmPrinter only needs support for emitting global variables, and is
otherwise a stub.
Depends on D127147
Differential Revision: https://reviews.llvm.org/D127153