Reland "[NewPM][CodeGen] Introduce CodeGenPassBuilder to help build codegen pipeline"
This reverts commit 94427af6 (relands
4646de5d with fix).
Use "return std::move(AsmStreamer);" instead of "return AsmStreamer;" in
LVMTargetMachine::createMCStreamer. Unlike Clang, GCC seems having trouble
inserting a implicit lvalue->rvalue conversion.