[Driver] [NetBSD] Pass default library search paths to linker

[mgorny]

Summary

Pass library search paths to linker as -L options, similarly to how
other toolchain drivers do it. This fixes compatibility with vanilla
LLD.

Bug report: https://bugs.llvm.org/show_bug.cgi?id=33155

// This is simplified version of D33726

[mgorny]

Gentle ping.

[ruiu]

Looks good but I'm probably not the right person to approve a change to this file.

[chandlerc]

There was a long discussion between two NetBSD maintainers about this (both already in the reviewers list of this patch). I'm not sure if there is an existing thread that would be better to follow up on as opposed to starting a fresh thread.

I think the question was: should the path search logic be handled in the clang driver or in LLD itself. FWIW, I prefer that NetBSD follow the same design as every other platform here with the (somewhat C and C++ specific) search logic provided by the clang driver.

lib/Driver/ToolChains/NetBSD.cpp

if (Args.hasArg(options::OPT_shared) || Args.hasArg(options::OPT_pie)) {
           Args.MakeArgString(ToolChain.GetFilePath("crtbeginS.o")));
     } else {
       CmdArgs.push_back(
           Args.MakeArgString(ToolChain.GetFilePath("crtbegin.o")));
     }
   }
 
   Args.AddAllArgs(CmdArgs, options::OPT_L);
+  ToolChain.AddFilePathLibArgs(Args, CmdArgs);
   Args.AddAllArgs(CmdArgs, options::OPT_T_Group);
   Args.AddAllArgs(CmdArgs, options::OPT_e);
   Args.AddAllArgs(CmdArgs, options::OPT_s);
   Args.AddAllArgs(CmdArgs, options::OPT_t);
   Args.AddAllArgs(CmdArgs, options::OPT_Z_Flag);
   Args.AddAllArgs(CmdArgs, options::OPT_r);
 
   bool NeedsSanitizerDeps = addSanitizerRuntimes(getToolChain(), Args, CmdArgs);