[WebAssembly] Remove invalid lld arguments

[sbc100]

Summary

These arguments don't (not yet at least) make sense for
the wasm lld port.

lib/Driver/ToolChains/WebAssembly.cpp

void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                 const char *LinkingOutput) const {
 
   const ToolChain &ToolChain = getToolChain();
   const char *Linker = Args.MakeArgString(ToolChain.GetLinkerPath());
   ArgStringList CmdArgs;
   CmdArgs.push_back("-flavor");
   CmdArgs.push_back("wasm");
 
-  // Enable garbage collection of unused input sections by default, since code
-  // size is of particular importance. This is significantly facilitated by
-  // the enabling of -ffunction-sections and -fdata-sections in
-  // Clang::ConstructJob.
-  if (areOptimizationsEnabled(Args))
-    CmdArgs.push_back("--gc-sections");
-
-  if (Args.hasArg(options::OPT_rdynamic))
-    CmdArgs.push_back("-export-dynamic");
   if (Args.hasArg(options::OPT_s))
     CmdArgs.push_back("--strip-all");
-  if (Args.hasArg(options::OPT_shared))
-    CmdArgs.push_back("-shared");
-  if (Args.hasArg(options::OPT_static))
-    CmdArgs.push_back("-Bstatic");
 
   Args.AddAllArgs(CmdArgs, options::OPT_L);
   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
 
-  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
-    if (Args.hasArg(options::OPT_shared))
-      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("rcrt1.o")));
-    else if (Args.hasArg(options::OPT_pie))
-      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
-    else
-      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt1.o")));
-
-    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
-  }
-
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
     if (ToolChain.ShouldLinkCXXStdlib(Args))
       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
 
     if (Args.hasArg(options::OPT_pthread))
       CmdArgs.push_back("-lpthread");
 
     CmdArgs.push_back("-allow-undefined-file");
     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("wasm.syms")));
     CmdArgs.push_back("-lc");
     CmdArgs.push_back("-lcompiler_rt");
   }
 
-  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles))
-    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtn.o")));
-
   CmdArgs.push_back("-o");
   CmdArgs.push_back(Output.getFilename());
 
   C.addCommand(llvm::make_unique<Command>(JA, *this, Linker, CmdArgs, Inputs));
 }
 
 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
                          const llvm::opt::ArgList &Args)