MC: Separate creating a generic object writer from creating a target object writer. NFCI.

With this we gain a little flexibility in how the generic object
writer is created.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47045

llvm-svn: 332868
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
index 8ec950d..a102197 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
@@ -211,9 +211,9 @@
   return Value;
 }
 
-std::unique_ptr<MCObjectWriter>
-MipsAsmBackend::createObjectWriter(raw_pwrite_stream &OS) const {
-  return createMipsELFObjectWriter(OS, TheTriple, IsN32);
+std::unique_ptr<MCObjectTargetWriter>
+MipsAsmBackend::createObjectTargetWriter() const {
+  return createMipsELFObjectWriter(TheTriple, IsN32);
 }
 
 // Little-endian fixup data byte ordering: