MCStreamer out of line

Author: rnk

llvm/include/llvm/Target/TargetMachine.h

@@ -490,9 +490,7 @@ class TargetMachine {
 
   virtual Expected<std::unique_ptr<MCStreamer>>
   createMCStreamer(raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
-                   CodeGenFileType FileType, MCContext &Ctx) {
-    return nullptr;
-  }
+                   CodeGenFileType FileType, MCContext &Ctx);
 
   /// True if the target uses physical regs (as nearly all targets do). False
   /// for stack machines such as WebAssembly and other virtual-register

llvm/lib/Target/TargetMachine.cpp

@@ -45,6 +45,12 @@ TargetMachine::TargetMachine(const Target &T, StringRef DataLayoutString,
 
 TargetMachine::~TargetMachine() = default;
 
+virtual Expected<std::unique_ptr<MCStreamer>>
+createMCStreamer(raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
+                 CodeGenFileType FileType, MCContext &Ctx) {
+  return nullptr;
+}
+
 bool TargetMachine::isLargeGlobalValue(const GlobalValue *GVal) const {
   if (getTargetTriple().getArch() != Triple::x86_64)
     return false;