MIR Serialization: Serialize the external symbol machine operands.

Reviewers: Duncan P. N. Exon Smith


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242806 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineFunction.h

@@ -475,6 +475,9 @@ public:
     extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
                         MachineInstr::mmo_iterator End);
 
+  /// Allocate a string and populate it with the given external symbol name.
+  const char *createExternalSymbolName(StringRef Name);
+
   //===--------------------------------------------------------------------===//
   // Label Manipulation.
   //