llvm-ar shouldn't need targets

[beanz]

Summary

There isn't any code in llvm-ar that actually uses targets, but it links them because it calls a few InitializeAll* functions. If we remove those calls, we can remove the dependency on the targets, which makes building llvm-ar a lot faster.

[• rafael]

It needs to be able to parse assembly in order to populate the symbol
table. No tests fail with this? I will add one if so.

[• rafael]

We already have Object/X86/archive-ir-asm.ll. Was it passing for you?

[beanz]

Ugh... I had completely overlooked generating symbol tables for assembly files. The layering oddness here kinda hurts my head and feels a bit off, but I get it.

I'll abandon this revision as my brain being out to lunch.

Thanks,
-Chris

tools/llvm-ar/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  ${LLVM_TARGETS_TO_BUILD}
   Core
   Object
   Support
   )
 
 add_llvm_tool(llvm-ar
   llvm-ar.cpp
   )

tools/llvm-ar/llvm-ar.cpp

int main(int argc, char **argv) {
 
   // Have the command line options parsed and handle things
   // like --help and --version.
   cl::ParseCommandLineOptions(argc, argv,
     "LLVM Archiver (llvm-ar)\n\n"
     "  This program archives bitcode files into single libraries\n"
   );
 
-  llvm::InitializeAllTargetInfos();
-  llvm::InitializeAllTargetMCs();
-  llvm::InitializeAllAsmParsers();
-
   StringRef Stem = sys::path::stem(ToolName);
   if (Stem.find("ar") != StringRef::npos)
     return ar_main();
   if (Stem.find("ranlib") != StringRef::npos)
     return ranlib_main();
   fail("Not ranlib or ar!");
 }