Split the object streamer callback in one per file format.

There are two main advantages to doing this

* Targets that only need to handle one of the formats specially don't have
  to worry about the others. For example, x86 now only registers a
  constructor for the COFF streamer.

* Changes to the arguments passed to one format constructor will not impact
  the other formats.

llvm-svn: 232699
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 4acf9fb..12005a1 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -1374,11 +1374,18 @@
   return new ARMTargetStreamer(S);
 }
 
+MCTargetStreamer *createARMObjectTargetStreamer(MCStreamer &S,
+                                                const MCSubtargetInfo &STI) {
+  Triple TT(STI.getTargetTriple());
+  if (TT.getObjectFormat() == Triple::ELF)
+    return new ARMTargetELFStreamer(S);
+  return new ARMTargetStreamer(S);
+}
+
 MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
                                     raw_ostream &OS, MCCodeEmitter *Emitter,
                                     bool RelaxAll, bool IsThumb) {
     ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
-    new ARMTargetELFStreamer(*S);
     // FIXME: This should eventually end up somewhere else where more
     // intelligent flag decisions can be made. For now we are just maintaining
     // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.