[Sanitizers] Don't use clang_rt.sancov_{begin,end} on Solaris

[ro]

Summary

As explained in https://reviews.llvm.org/D63601, there's no point using clang_rt.sancov_{begin,end}
on Solaris any longer.

This companion patch to the above removes their use from the driver.

Tested on amd64-pc-solaris2.11, ok for trunk?

[ro]

Ping? It's been a week and I've since been informed that without it Solaris/SPARC compilation is broken since the sancov_* archives don't
exit (compiler-rt isn't built on sparc).

[ro]

Ping^2. This one, like its companion https://reviews.llvm.org/D63601 has remained unreviewed for two weeks.

[vitalybuka]

In D63602#1570884, @ro wrote:

Ping^2. This one, like its companion https://reviews.llvm.org/D63601 has remained unreviewed for two weeks.

I would recommend to check for a recent activity of the reviewer and here I would not expect anything from @alekseyshl

[ro]

In D63602#1574337, @vitalybuka wrote:

In D63602#1570884, @ro wrote:

Ping^2. This one, like its companion https://reviews.llvm.org/D63601 has remained unreviewed for two weeks.

I would recommend to check for a recent activity of the reviewer and here I would not expect anything from @alekseyshl

Good point, thanks: I'll heed that in the future. So far, Iv'e been going by the CODE_OWNERS.TXT files just like GCC's MAINTAINERS. However,
even there you know after a time which maintainer is currently active.

lib/Driver/ToolChains/Solaris.cpp

if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
 
     CmdArgs.push_back(Args.MakeArgString(getToolChain().GetFilePath("crti.o")));
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath("values-Xa.o")));
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath("crtbegin.o")));
   }
 
-  // Provide __start___sancov_guards.  Solaris ld doesn't automatically create
-  // __start_SECNAME labels.
-  CmdArgs.push_back("--whole-archive");
-  CmdArgs.push_back(
-      getToolChain().getCompilerRTArgString(Args, "sancov_begin"));
-  CmdArgs.push_back("--no-whole-archive");
-
   getToolChain().AddFilePathLibArgs(Args, CmdArgs);
 
   Args.AddAllArgs(CmdArgs, {options::OPT_L, options::OPT_T_Group,
                             options::OPT_e, options::OPT_r});
 
   bool NeedsSanitizerDeps = addSanitizerRuntimes(getToolChain(), Args, CmdArgs);
   AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs, JA);
 
if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
     if (!Args.hasArg(options::OPT_shared)) {
       CmdArgs.push_back("-lgcc");
       CmdArgs.push_back("-lm");
     }
     if (NeedsSanitizerDeps)
       linkSanitizerRuntimeDeps(getToolChain(), CmdArgs);
   }
 
-  // Provide __stop___sancov_guards.  Solaris ld doesn't automatically create
-  // __stop_SECNAME labels.
-  CmdArgs.push_back("--whole-archive");
-  CmdArgs.push_back(
-      getToolChain().getCompilerRTArgString(Args, "sancov_end"));
-  CmdArgs.push_back("--no-whole-archive");
-
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath("crtend.o")));
   }
   CmdArgs.push_back(Args.MakeArgString(getToolChain().GetFilePath("crtn.o")));
 
   getToolChain().addProfileRTLibs(Args, CmdArgs);