Add a MCTargetStreamer interface.

This patch fixes an old FIXME by creating a MCTargetStreamer interface
and moving the target specific functions for ARM, Mips and PPC to it.

The ARM streamer is still declared in a common place because it is
used from lib/CodeGen/ARMException.cpp, but the Mips and PPC are
completely hidden in the corresponding Target directories.

I will send an email to llvmdev with instructions on how to use this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192181 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index 0ed040d..c16a61d 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -560,15 +560,12 @@
   this->MCObjectStreamer::FinishImpl();
 }
 
-void MCELFStreamer::EmitTCEntry(const MCSymbol &S) {
-  // Creates a R_PPC64_TOC relocation
-  MCObjectStreamer::EmitSymbolValue(&S, 8);
-}
-
-MCStreamer *llvm::createELFStreamer(MCContext &Context, MCAsmBackend &MAB,
-                                    raw_ostream &OS, MCCodeEmitter *CE,
-                                    bool RelaxAll, bool NoExecStack) {
-  MCELFStreamer *S = new MCELFStreamer(Context, MAB, OS, CE);
+MCStreamer *llvm::createELFStreamer(MCContext &Context,
+                                    MCTargetStreamer *Streamer,
+                                    MCAsmBackend &MAB, raw_ostream &OS,
+                                    MCCodeEmitter *CE, bool RelaxAll,
+                                    bool NoExecStack) {
+  MCELFStreamer *S = new MCELFStreamer(Context, Streamer, MAB, OS, CE);
   if (RelaxAll)
     S->getAssembler().setRelaxAll(true);
   if (NoExecStack)