[Driver] Replace a link to openradar with a comment. NFC

[MaskRay]

https://openradar.appspot.com/7198997 says Date Originated: 04-Sep-2009 06:00 PM. Is the very old linker bug still relevant?

[ahatanak]

Mention that the linker bug has been fixed.

[ahatanak]

It looks like the linker bug has been fixed, but we probably need extensive testing before enabling it on Darwin.

clang/lib/Driver/ToolChains/Clang.cpp

if (Args.hasArg(options::OPT_fdebug_pass_structure)) {
     CmdArgs.push_back("Structure");
   }
   if (Args.hasArg(options::OPT_fdebug_pass_arguments)) {
     CmdArgs.push_back("-mdebug-pass");
     CmdArgs.push_back("Arguments");
   }
 
   // Enable -mconstructor-aliases except on darwin, where we have to work around
-  // a linker bug (see https://openradar.appspot.com/7198997), and CUDA device
-  // code, where aliases aren't supported.
+  // a linker bug where aliasing symbols are not moved to the new locations when
+  // the aliased symbol is moved, and CUDA device code, where aliases aren't
+  // supported.
+  // FIXME: Enable this on Darwin after extensive testing. The linker bug
+  // mentioned above has been fixed.
   if (!RawTriple.isOSDarwin() && !RawTriple.isNVPTX())
     CmdArgs.push_back("-mconstructor-aliases");
 
   // Darwin's kernel doesn't support guard variables; just die if we
   // try to use them.
   if (KernelOrKext && RawTriple.isOSDarwin())
     CmdArgs.push_back("-fforbid-guard-variables");